ofTexture documentation

Merged documentation from ofSite, and added named groups.
Clean up text.
Punctuation and spacing.
Clean up and line length.
Clean up, spacing, grammar, line length.
Spacing.
Cleanup and being more specific.
Additional comments, corrections, etc.
Add docs in ofBaseDraw to allow doc inheritance.
Formattings.
Continued fixes.
Merge pull request #3465 from bakercp/documentation-oftexture

Documentation oftexture