glPatchParameter / GL_PATCHES missing

[bananu7]

Despite tesselation shaders exposed, important functions regarding them are missing from the bindings.

[hesiod]

This is basically solved by #74. Some of the (more unimportant) implementation limits are still missing, but could easily be added if someone needs them.

[svenpanne]

@hesiod : I've tweaked #74 a bit yesterday (see df5dc42). @bananu7: In addition to what's already there, what exactly is important/urgent for you from the tesselation API? At one point I'll do a thorough review of the tessellation functionality, but if there's something easy I can add this quickly.

[hesiod]

@svenpanne: I'm not @bananu7, but as far as I understand, only some boring implementation limits (e.g. MAX_TESS_CONTROL_UNIFORM_COMPONENTS) and default values (e.g. PATCH_DEFAULT_OUTER_LEVEL) are missing.

[bananu7]

Mmm, this is over a year old, @svenpanne, so it's hardly urgent 😄 . I rember trying to port a simple tesselation demo, failing, posting an issue and never going back to it.

That being said, I think doing things completely (as in, adding even those boring limits) can solve problems with someone, somewhere needing them later. Boring and tedious, but that's what OpenGL is about :)