== python api doc ==

First commit to make some structure in doc/ directory.

- moved source/blender/python/doc -> doc/python_api
- moved source/gameengine/PyDoc/*.rst -> doc/python_api/rst
- modified accordingly sphinx_doc_gen.py and sphinx_doc_gen.sh
  (later on I'll try alternative/ scripts by neXyon as promised :)
- source/gameengine/PyDoc/ is still there because contains epydoc stuff for the bge, will ask more and look into it later

doc/python_api/examples/mathutils.py

@@ -0,0 +1,18 @@
+import mathutils
+from math import radians
+
+vec = mathutils.Vector((1.0, 2.0, 3.0))
+
+mat_rot = mathutils.Matrix.Rotation(radians(90), 4, 'X')
+mat_trans = mathutils.Matrix.Translation(vec)
+
+mat = mat_trans * mat_rot
+mat.invert()
+
+mat3 = mat.rotation_part()
+quat1 = mat.to_quat()
+quat2 = mat3.to_quat()
+
+angle = quat1.difference(quat2)
+
+print(angle)