memcpyCudaOpenGL: Add support for 32-Bit builds, and actually build 64-Bit Windows support.

Update the makefile to also support 32-Bit builds on all operating
systems. However, we won't actually build mex files for 32-Bit Matlab's
anytime soon.

Add support and build mex file for 64-Bit Matlab on 64-Bit MS-Windows.
-> memcpyCudaOpenGL.mexw64 built and tested.