Found an easy way to go from glm to old openGL context, without
using osg::Matrix.  Now old graphics can translate using
GlmTranslation.
Graphic now sets the linewidth correctly, albeit it is a deprecated method
that will be changed in the future (when OpenGL specs remove glLineWidth).

Implemented the glMapBuffer functionality, which will gain performance
by getting pointers directly to the GPU memory for dynamic drawing.

Removed small warnings.