Keyboard Key Mapping 'DONE' for OS X and Windows 

These 2 OS's would be ready for more testing / feedback from others on key mapping to event .key and .char fields. Use demos/coder/iohub/keyboard.py to test.

For list of know issues / todo's for keyboard mapping:

* OSX: https://github.com/isolver/psychopy/issues/18
* Windows: https://github.com/isolver/psychopy/issues/16 (unckecked comment items)

My Debian VM seems to be dead, so have to reinstall before finishing up this on linux. ;(