Improved features for git-hack
Allow autocompletion of git branches for all Git commands

This is safer. The old way prevented autocompletion for normal
Git commands.
Improved features for git-town
resolves #199: command list architecture
Add missing feature specs for git ship
Missing feature specs for git kill
Improved features for git-extract
Improved features for git-prune-branches
Improved features for git-kill
Merge branch 'master' into aw-finish-config

Conflicts:
	features/git-town/help.feature