fix GitGutterToggle mapping in vimrc
Remove `brew update` from install

`brew` is often broken on people's systems if it's been installed for a while.
Installing maximum-awesome is *not* the right way to find out.
Merge pull request #27 from dhoizner/fix/toggle_git_gutter

fix GitGutterToggle mapping in vimrc
Merge pull request #44 from square/remove-brew-update

Remove `brew update` from install
Replace Command-T with CtrlP.vim
Update README
Back ctrlp with ag, because it's super fast

Also, I think we should definitely clear the cache when vim exits - imagine
switching branches, opening vim and not finding your files.
Bring back caching
Merge pull request #41 from square/riley/ctrlp

Replace Cmd-T with Ctrl-P
Merge remote-tracking branch 'upstream/master'

Conflicts:
	vimrc
Added vundle as a step in Rake
Moved all submodules to .vimrc.bundles
Removed all submodules as they are now fetched with vundle