Add Shift Keys to Parens

This patch adds the option to remap the shift keys to the appropriate parenthesis when they are pressed without any other key, as seen in http://stevelosh.com/blog/2012/10/a-modern-space-cadet/#better-shifting

I added a new category for options pertaining to both shift keys instead of just one, not sure if that was correct.

Also, I wrote this with the stable version 7.8, but I updated the definition to match the changes I saw.