Update homebrew install script url

Home homebrew install Gist (https://raw.github.com/gist/323731) has been removed. New link (https://raw.github.com/mxcl/homebrew/go) taken from official website (http://mxcl.github.com/homebrew/)
Update link to @sorin-ionescu Oh My Zsh

Oh My Zsh fork now renamed to Prezto
Merge pull request #129 from JeanMertz/patch-2

Update link to @sorin-ionescu Oh My Zsh
Merge pull request #127 from JeanMertz/patch-1

Update homebrew install script url
enabling theme changes when using prezto through zsh before
(cherry picked from commit 1cccb0e9c522654b7976bea047ed6f9f221ee510)
Updated reference to prezto (omz sorin)
Handle systems without rvm [Close #130]
Swap all references of oh-my-zsh to Prezto
Remove zsh/prezto custom directory in favor of submodule
Add Prezto submodule
Add simple Prezto installation
Moved to experimental Prezto branch
Set correct PDIR location in zshenv
Remove git.zsh, it is not useful [Close #135]
Uses vim/after directory instead of root for custom vimrc.after
Added original implementation for janus overrides
Updated README
Added vimrc.after to gitignore
Merge pull request #141 from corroded/relative_vim_overrides

Uses vim/after directory instead of root for custom vimrc.after
Update prezto submodule