Add basic 'emacs style' key bindings.

Could do with being smarter to properly handle C-w and add C-k but this is a good start.
Allow the CCPREFIX to be overridden by the command line.
Fix building on OSX (both cross and normal)
- Building natively on OSX is no different to Linux.
- When building embedded specify -nostartfiles and then add the bare libraries required.
Fix cut & paste error (don't link to libm as there is a custom one)
Allow the user to specify the color order.
Add HSV color routines.
Merge pull request #417 from DanielO/master

Emacs bindings, misc build fixes