Codex: CSM formations and ammendments

Version 109:

Added Kharns Butcherhorde as a formation.

Added a shared entry for VoTLW. Re-linked Bikers and Lord to use the
shared entry. Added modifiers to lock their usage in Crimson Slaughter
and Black Legion to as required.

Version 110: Fixed unit cost and rules for the Butcherhorde formation.