Moves [cmd] + [shft] + O to be used for open quickly dialog

This moves the keybinding back to RM default key bindings and is more in sync with OSX general preferences for quick open.  It was previously bound to open project which is such a rare thing to need to do that it does not need it's own key binding.
Merge pull request #13 from codeword/cmd_o_quick_open

Moves [cmd] + [shft] + O to be used for open quickly dialog