* vendor: sync to latest core

* dex, core: fix conflict

x

To discourage DKG set from prolonging the round indefinitely, we set the
block reward of the extended round to 0. The gas fee is send to the
DEXON governance owner for safe keeping and later used by the foundation.

Since a qualified node might fail stopped, we need to remove them from
qualified nodes to maintain network integrity. We do this by inspect the
previous round to see if there are dead nodes. A dead node is a notary
set node that does not propose any block in the previous round. We
disqualify them by fining them so their staked value is 1 wei below
minStake. This make them unqualified for being notary set in the follow
on rounds.

* change default sync_core.sh
* vendor: sync to latest core
* core: Remove K, Phi and NumChain

Instead of having BP to send a tx to register the round height, just
modify the state when finalizing block.

Refactor GenerateDexonChain function, move governance tx logic to
the user of GenerateDexonChain (testchain_test.go) and move fake node set
code to FakeDexcon.