Moved color into Sigma namespace

Color is now part of the Sigma namespace.

Also GLMesh has more helper methods to add various vertex data.
GLIcoSphere now uses GLMesh

GLIcoSphere now stores its vertex data in a GLMesh. This will allow
better flexibility is making it easier to maintain the various drawing
of mesh style data.
GLIcoSphere is now a GLMesh

Instead of a has-a it is now an is-a.
Added checks to GLMesh for rebuffering

GLMesh will now rebuffer all data if Initialize() is called again. This
doesn't create new buffers it just overwrites existing ones.

Also RemoveFace() is fleshed out.
Completed RefineFace() in GLIcoSphere

RefineFace() new properly refines a face minus the normal. However there
is a definite issue with adjacent faces being at different levels now.

For now the code is commented out until a better way to handle this is
decided on.
Merge branch 'develop' of https://github.com/adam4813/Sigma into develop