Add bip68/112/113 and optimizations.

Optimizations, dust, tx pool finality, fix coinbase pattern.

Store compression, fixes and improvements.

Major new features and improved quality.

Fix unguarded signature op codes.

Required by bs v2.4.0.

Update block version error message text.

Required by bs v2.2.0 and bx v2.2.0.

Required server v2.1.0.

Required by bx v2.1.0 and server v2.0.0.