Godeps, vendor: convert dependency management to trash (#3198)

This commit converts the dependency management from Godeps to the vendor
folder, also switching the tool from godep to trash. Since the upstream tool
lacks a few features proposed via a few PRs, until those PRs are merged in
(if), use github.com/karalabe/trash.

You can update dependencies via trash --update.

All dependencies have been updated to their latest version.

Parts of the build system are reworked to drop old notions of Godeps and
invocation of the go vet command so that it doesn't run against the vendor
folder, as that will just blow up during vetting.

The conversion drops OpenCL (and hence GPU mining support) from ethash and our
codebase. The short reasoning is that there's noone to maintain and having
opencl libs in our deps messes up builds as go install ./... tries to build
them, failing with unsatisfied link errors for the C OpenCL deps.

golang.org/x/net/context is not vendored in. We expect it to be fetched by the
user (i.e. using go get). To keep ci.go builds reproducible the package is
"vendored" in build/_vendor.

1 files changed, 194 insertions, 0 deletions

diff --git a/vendor/github.com/davecgh/go-spew/README.md b/vendor/github.com/davecgh/go-spew/README.md
new file mode 100644
index 000000000..556170ae6
--- /dev/null
+++ b/vendor/github.com/davecgh/go-spew/README.md
@@ -0,0 +1,194 @@
+go-spew
+=======
+
+[![Build Status](https://travis-ci.org/davecgh/go-spew.png?branch=master)]
+(https://travis-ci.org/davecgh/go-spew) [![Coverage Status]
+(https://coveralls.io/repos/davecgh/go-spew/badge.png?branch=master)]
+(https://coveralls.io/r/davecgh/go-spew?branch=master)
+
+Go-spew implements a deep pretty printer for Go data structures to aid in
+debugging.  A comprehensive suite of tests with 100% test coverage is provided
+to ensure proper functionality.  See `test_coverage.txt` for the gocov coverage
+report.  Go-spew is licensed under the liberal ISC license, so it may be used in
+open source or commercial projects.
+
+If you're interested in reading about how this package came to life and some
+of the challenges involved in providing a deep pretty printer, there is a blog
+post about it
+[here](https://web.archive.org/web/20160304013555/https://blog.cyphertite.com/go-spew-a-journey-into-dumping-go-data-structures/).
+
+## Documentation
+
+[![GoDoc](https://godoc.org/github.com/davecgh/go-spew/spew?status.png)]
+(http://godoc.org/github.com/davecgh/go-spew/spew)
+
+Full `go doc` style documentation for the project can be viewed online without
+installing this package by using the excellent GoDoc site here:
+http://godoc.org/github.com/davecgh/go-spew/spew
+
+You can also view the documentation locally once the package is installed with
+the `godoc` tool by running `godoc -http=":6060"` and pointing your browser to
+http://localhost:6060/pkg/github.com/davecgh/go-spew/spew
+
+## Installation
+
+```bash
+$ go get -u github.com/davecgh/go-spew/spew
+```
+
+## Quick Start
+
+Add this import line to the file you're working in:
+
+```Go
+import "github.com/davecgh/go-spew/spew"
+```
+
+To dump a variable with full newlines, indentation, type, and pointer
+information use Dump, Fdump, or Sdump:
+
+```Go
+spew.Dump(myVar1, myVar2, ...)
+spew.Fdump(someWriter, myVar1, myVar2, ...)
+str := spew.Sdump(myVar1, myVar2, ...)
+```
+
+Alternatively, if you would prefer to use format strings with a compacted inline
+printing style, use the convenience wrappers Printf, Fprintf, etc with %v (most
+compact), %+v (adds pointer addresses), %#v (adds types), or %#+v (adds types
+and pointer addresses): 
+
+```Go
+spew.Printf("myVar1: %v -- myVar2: %+v", myVar1, myVar2)
+spew.Printf("myVar3: %#v -- myVar4: %#+v", myVar3, myVar4)
+spew.Fprintf(someWriter, "myVar1: %v -- myVar2: %+v", myVar1, myVar2)
+spew.Fprintf(someWriter, "myVar3: %#v -- myVar4: %#+v", myVar3, myVar4)
+```
+
+## Debugging a Web Application Example
+
+Here is an example of how you can use `spew.Sdump()` to help debug a web application. Please be sure to wrap your output using the `html.EscapeString()` function for safety reasons. You should also only use this debugging technique in a development environment, never in production.
+
+```Go
+package main
+
+import (
+    "fmt"
+    "html"
+    "net/http"
+
+    "github.com/davecgh/go-spew/spew"
+)
+
+func handler(w http.ResponseWriter, r *http.Request) {
+    w.Header().Set("Content-Type", "text/html")
+    fmt.Fprintf(w, "Hi there, %s!", r.URL.Path[1:])
+    fmt.Fprintf(w, "<!--\n" + html.EscapeString(spew.Sdump(w)) + "\n-->")
+}
+
+func main() {
+    http.HandleFunc("/", handler)
+    http.ListenAndServe(":8080", nil)
+}
+```
+
+## Sample Dump Output
+
+```
+(main.Foo) {
+ unexportedField: (*main.Bar)(0xf84002e210)({
+  flag: (main.Flag) flagTwo,
+  data: (uintptr) <nil>
+ }),
+ ExportedField: (map[interface {}]interface {}) {
+  (string) "one": (bool) true
+ }
+}
+([]uint8) {
+ 00000000  11 12 13 14 15 16 17 18  19 1a 1b 1c 1d 1e 1f 20  |............... |
+ 00000010  21 22 23 24 25 26 27 28  29 2a 2b 2c 2d 2e 2f 30  |!"#$%&'()*+,-./0|
+ 00000020  31 32                                             |12|
+}
+```
+
+## Sample Formatter Output
+
+Double pointer to a uint8:
+```
+	  %v: <**>5
+	 %+v: <**>(0xf8400420d0->0xf8400420c8)5
+	 %#v: (**uint8)5
+	%#+v: (**uint8)(0xf8400420d0->0xf8400420c8)5
+```
+
+Pointer to circular struct with a uint8 field and a pointer to itself:
+```
+	  %v: <*>{1 <*><shown>}
+	 %+v: <*>(0xf84003e260){ui8:1 c:<*>(0xf84003e260)<shown>}
+	 %#v: (*main.circular){ui8:(uint8)1 c:(*main.circular)<shown>}
+	%#+v: (*main.circular)(0xf84003e260){ui8:(uint8)1 c:(*main.circular)(0xf84003e260)<shown>}
+```
+
+## Configuration Options
+
+Configuration of spew is handled by fields in the ConfigState type. For
+convenience, all of the top-level functions use a global state available via the
+spew.Config global.
+
+It is also possible to create a ConfigState instance that provides methods
+equivalent to the top-level functions. This allows concurrent configuration
+options. See the ConfigState documentation for more details.
+
+```
+* Indent
+	String to use for each indentation level for Dump functions.
+	It is a single space by default.  A popular alternative is "\t".
+
+* MaxDepth
+	Maximum number of levels to descend into nested data structures.
+	There is no limit by default.
+
+* DisableMethods
+	Disables invocation of error and Stringer interface methods.
+	Method invocation is enabled by default.
+
+* DisablePointerMethods
+	Disables invocation of error and Stringer interface methods on types
+	which only accept pointer receivers from non-pointer variables.  This option
+	relies on access to the unsafe package, so it will not have any effect when
+	running in environments without access to the unsafe package such as Google
+	App Engine or with the "safe" build tag specified.
+	Pointer method invocation is enabled by default.
+
+* ContinueOnMethod
+	Enables recursion into types after invoking error and Stringer interface
+	methods. Recursion after method invocation is disabled by default.
+
+* SortKeys
+	Specifies map keys should be sorted before being printed. Use
+	this to have a more deterministic, diffable output.  Note that
+	only native types (bool, int, uint, floats, uintptr and string)
+	and types which implement error or Stringer interfaces are supported,
+	with other types sorted according to the reflect.Value.String() output
+	which guarantees display stability.  Natural map order is used by
+	default.
+
+* SpewKeys
+	SpewKeys specifies that, as a last resort attempt, map keys should be
+	spewed to strings and sorted by those strings.  This is only considered
+	if SortKeys is true.
+
+```
+
+## Unsafe Package Dependency
+
+This package relies on the unsafe package to perform some of the more advanced
+features, however it also supports a "limited" mode which allows it to work in
+environments where the unsafe package is not available.  By default, it will
+operate in this mode on Google App Engine and when compiled with GopherJS.  The
+"safe" build tag may also be specified to force the package to build without
+using the unsafe package.
+
+## License
+
+Go-spew is licensed under the liberal ISC License.