Add same computation on available GPU Backends: CUDA, OpenCL, OpenGL

A run on my ACER Aspire V3-571G, Windows8_x64 gives:
SGEMM: Single-precision General Matrix Multiply
Compute MxM with a Square MATRIX SIZE = 256
Same code but many ways:

- Basic C language computation: the for(i, j, k) loop
- CPU device Backend
- GPU / CUDA Backend
- GPU / OpenCL Backend
- GPU / OpenGL Backend
- Cloud Computing on local node

Let's Start...

*********** Basic ***********
Total time : 92.2532 milliseconds
0.363011 GFlop/s.

********** CPU 1 **********

CPU Backend SET
Total time : 2.21056 milliseconds
15.1495 GFlop/s.

********** GPU 1 **********

CUDA Backend SET
Total time : 1.0362 milliseconds
32.319 GFlop/s.

OpenCL Backend cannot be set

OpenGL Backend SET
Total time : 3.61189 milliseconds
9.27185 GFlop/s.

********** CLOUD **********

Cloud cannot be SET
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