pybullet: add option to use NumPy to speed up, thanks to moof2k

option is disabled by default. When using cmake, use
cmake -DBUILD_PYBULLET=ON -DBUILD_PYBULLET_NUMPY=ON
then both testrender.py and testrender_np.py will work
without numpy only testrender.py works.
The numpy.reshape is likely a no-op when using numpy array,
so we could remove testrender_np.py...

See https://github.com/bulletphysics/bullet3/pull/774

examples/pybullet/CMakeLists.txt

@@ -5,6 +5,11 @@ INCLUDE_DIRECTORIES(
 		${BULLET_PHYSICS_SOURCE_DIR}/examples/ThirdPartyLibs
 		${PYTHON_INCLUDE_DIRS}
   )
+IF(BUILD_PYBULLET_NUMPY)
+	INCLUDE_DIRECTORIES(
+		${PYTHON_NUMPY_INCLUDE_DIR}
+	)
+ENDIF()
 
 SET(pybullet_SRCS
 	pybullet.c