GitLab

In this commit, the option only works for git but it should not be to hard for
someone who knows svn to so the same.
This commit is largely inspired by @yoavweiss, I only added an option to use
it.

Example aliases allow for an easier way to open ZSH config file/folder
in Textmate. New theme is mh.zsh-theme.

After a few weeks of using this, I'd prefer this to not be enabled by default. My bad for suggesting that in the first place.

This reverts commit fc49b4a4.

Feature: Random themes now supported. Just set your theme to 'random' and it'll load a different theme each time oh-my-zsh is started. Closes #309

These variables are only used by oh-my-zsh, so there's no need
to populate the environment of all children with them.

Updating install process to copy your current environments PATH and adding it to the bottom of ~/.zshrc.