option to build the BGE without python, uses existing python check (cmake and scons)

when python is disabled videotextures are not built.

source/gameengine/Ketsji/KX_ArmatureSensor.cpp

@@ -153,6 +153,7 @@ bool KX_ArmatureSensor::Evaluate()
 	return (reset) ? true : false;
 }
 
+#ifndef DISABLE_PYTHON
 
 /* ------------------------------------------------------------------------- */
 /* Python functions                                                          */
@@ -203,3 +204,5 @@ PyObject* KX_ArmatureSensor::pyattr_get_constraint(void *self, const struct KX_P
 	}
 	Py_RETURN_NONE;
 }
+
+#endif // DISABLE_PYTHON