cmd/evm, core/vm, test: refactored VM and core

* Moved `vm.Transfer` to `core` package and changed execution to call
`env.Transfer` instead of `core.Transfer` directly.
* core/vm: byte code VM moved to jump table instead of switch
* Moved `vm.Transfer` to `core` package and changed execution to call
  `env.Transfer` instead of `core.Transfer` directly.
* Byte code VM now shares the same code as the JITVM
* Renamed Context to Contract
* Changed initialiser of state transition & unexported methods
* Removed the Execution object and refactor `Call`, `CallCode` &
  `Create` in to their own functions instead of being methods.
* Removed the hard dep on the state for the VM. The VM now
  depends on a Database interface returned by the environment. In the
  process the core now depends less on the statedb by usage of the env
* Moved `Log` from package `core/state` to package `core/vm`.

1 files changed, 32 insertions, 0 deletions

diff --git a/core/vm/doc.go b/core/vm/doc.go
new file mode 100644
index 000000000..4deb7761d
--- /dev/null
+++ b/core/vm/doc.go
@@ -0,0 +1,32 @@
+// Copyright 2014 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+/*
+Package vm implements the Ethereum Virtual Machine.
+
+The vm package implements two EVMs, a byte code VM and a JIT VM. The BC
+(Byte Code) VM loops over a set of bytes and executes them according to a set
+of rules defined in the Ethereum yellow paper. When the BC VM is invokes it
+invokes the JIT VM in a seperate goroutine and compiles the byte code in JIT
+instructions.
+
+The JIT VM, when invoked, loops around a set of pre-defined instructions until
+it either runs of gas, causes an internel error, returns or stops. At a later
+stage the JIT VM will see some additional features that will cause sets of
+instructions to be compiled down to segments. Segments are sets of instructions
+that can be ran in one go saving precious time during execution.
+*/
+package vm