Added hub completion which works around a bug in the version that ships with hub.

This can go away once this patch is merged:
https://github.com/defunkt/hub/pull/295
Disable login/logout messages
Set Sublime Text as the default editor.
Enable syntax highlighting
Added boxen support.
Enable node support
Enable Ruby support
Disable Ruby aliases
Enable git support
Disable git aliases
Make tab completion case-sensitive
Fix for using a carrot in commands ("git reset HEAD^^")
Disable emacs key mappings
Handy function to toss your ssh key onto a remote machine
Misc aliases
Customize prompt