Minor speedups for the BGE

* Where possible use vec.setValue(x,y,z) to assign values to a vector instead of vec= MT_Vector3(x,y,z), for MT_Point and MT_Matrix types too.
* Comparing TexVerts was creating 10 MT_Vector types - instead compare as floats.
* Added SG_Spatial::SetWorldFromLocalTransform() since the local transform is use for world transform in some cases.
* removed some unneeded vars from UpdateChildCoordinates functions 
* Py API - Mouse, Ray, Radar sensors - use PyObjectFrom(vec) rather then filling the lists in each function. Use METH_NOARGS for get*() functions.

source/gameengine/SceneGraph/SG_BBox.cpp

@@ -34,8 +34,8 @@
  #include "SG_Node.h"
  
 SG_BBox::SG_BBox() :
-	m_min(MT_Point3(0., 0., 0.)),
-	m_max(MT_Point3(0., 0., 0.))
+	m_min(0., 0., 0.),
+	m_max(0., 0., 0.)
 {
 }