fix OSX keybindings (super+space doesn't work)
fix OSX keybindings (super+space doesn't work)

`command` + `space` is a global keybinding in OSX to trigger
Spotlight. I chose `shift` instead of `ctrl` or `alt` as the
modifier key because those are popular shortcuts for the Alfred
app (http://support.alfredapp.com/kb:cmd-space)
alexmullins/GoSublime,FWennerdahl/GoSublime,DisposaBoy/GoSublime,justinfx/GoSublime,allgeek/GoSublime,dlclark/GoSublime,dlclark/GoSublime,DisposaBoy/GoSublime-next,anacrolix/GoSublime,allgeek/GoSublime,allgeek/GoSublime,nathany/GoSublime,cdht/GoSublime,nathany/GoSublime,DisposaBoy/GoSublime,simman/GoSublime,DisposaBoy/GoSublime-next,justinfx/GoSublime,Mistobaan/GoSublime,Mistobaan/GoSublime,simman/GoSublime,simman/GoSublime,cdht/GoSublime,nathany/GoSublime,anacrolix/GoSublime,DisposaBoy/GoSublime-next,cdht/GoSublime,alexmullins/GoSublime,FWennerdahl/GoSublime,FWennerdahl/GoSublime,Mistobaan/GoSublime,alexmullins/GoSublime,anacrolix/GoSublime