Add support for backface properties

Added support for backface properties in the OpenGL2 backend.
Also cleaned up some spacing for some of the string replacements
and moved some of them into a seperate ufnction as it was getting
rather large.

Change-Id: Iaaae0e4af531d9cfb9cc08d907827399046a1e6b
Merge topic 'add_backface_properties' into master

e7b395e1 Add support for backface properties