Revert "Always go for the Command key binding on the mac. We leave"

This change appears to make arrow keys stop working Mac OSX (10.8).

This reverts commit 0e186efed1fa794972d3203ec4e99f48fc6d7c82.
Merge pull request #443 from blipvert/fixes/11

Revert "Always go for the Command key binding on the mac."
Test to see if command key is pressed and control key is not pressed
before proceeding to substitute control key.
Merge pull request #444 from blipvert/fixes/11

Test to see if command key is pressed and control key is not pressed before proceeding to substitute control key.