PoS integration work
Merge branch 'mably' into kac

Conflicts:
	chain.go
getStakeEntropyBit, code formatting
some
ShaHashToBig utilization
ShaHashToBig utilization
moved peercoin specific parts to ppc.go
Merge branch 'mably' of https://github.com/mably/btcchain into mably
Merge branch 'mably' into kac
Small code cleaning and reorg
Small code cleaning and reorg
Merge branch 'mably' of https://github.com/mably/btcchain into mably
Peercoin PoS metadata management