Added antigen submodule to repo
Removed snipmate from vim plugins

Didn't really use it anyway, and repository has disappeared.
Zsh now uses antigen for plugin loading
Added zsh-completions
Added some more oh-my-zsh plugins
Set git credential helper to osxkeychain
Vim now uses vundle for plugin management
Stripped out redundant setup.py code

Now that I'm using vundle & antigen, lots of the code in setup.py is now
redundant.  This commit removes the redundant code.
Merge branch 'master' into overhaul

Conflicts:
	_zshrc
Fixed profile & localrc loading in _zshrc

Previously were loaded before all the zsh plugins, leading to path
problems.