Partially revert 35e061a, unconditionally sign pow2 steemit#256

fix signature on pow transaction when not needed, update hardfork time …

…steemit#256

increase floor, fix build

increase floor, fix build

Merge branch 'staging'

bump version

Merge branch 'staging' v0.12.1

Merge branch 'staging' v0.12.0

Fix hardfork constant

Merge branch 'staging'