refactored direct manipulation of constraints to showMenu/hideMenu functions
add some stuff to sidebar
added FontAwesome and its license details
change sidebar width from 160 to 180
a bunch of sidebar stuff with table view and laid out user heading view
programmatically generate menu items into tableview
added stubs for mentions view, settings view
laid out profile view controller but not working yet (outlets are nil?)
added log out functionality
updated screencap and readme
Merge pull request #6 from jontsai/master

a bunch of updates