patch [#27909] Added constants in bge.constraints by Solano Felicio (solano) + some changes in rst

I named all the BGE modules with their actual names (e.g. Rasterizer, Video Texture, ...). so in the API index.html page they look more like the other Blender modules.
I did the same for the bgl module.

For bge.constraints this patch exposes the constants values for debug mode and createConstraints (they were hardcoded innts before).

+ making all the "todo" and #comments into rst comments (.. comments)
Thanks Solano, it's great to get help to those tasks :)

doc/python_api/rst/bge.texture.rst

@@ -1,11 +1,7 @@
 
-Game Engine bge.texture Module
+Video Texture (bge.texture)
 ==============================
 
-.. note::
-   This documentation is still very weak, and needs some help! Right now they are mostly a collection
-   of the docstrings found in the bge.texture source code + some random places filled with text.
-
 *****
 Intro
 *****