Add "Commits" plugin

I borrowed this from ContextBot:
http://subforge.org/projects/shreds/repository/entry/bot/cinch.rb
Add "Classname" plugin

I borrowed this from ContextBot:
http://subforge.org/projects/shreds/repository/entry/bot/cinch.rb
Add "Phrases" plugin

Ported from ContextBot:
http://subforge.org/projects/shreds/repository/entry/bot/cinch.rb
phrases.rb: fix typo
classname.rb: fix typos