CUDA - standard optimization test functions

[jairodelgado]

This issue is a continuation of issue #10.

We need to implement the following test functions in parallel using CUDA, that is in cudalayer:

• Ackley
• Alpine
• De Jung
• Griewangk
• Rastrigin
• Rosenbrock
• Schwefel
• Step
• Styblinski_tang
• Brown Function
• Chung Reynolds Function
• Cosine Mixture Function
• Csendes Function
• Deb 1 Function
• Deb 3 Function
• Dixon & Price Function
• Egg Holder Function
• Exponential Function
• Giunta Function

Each function specification can be found in: http://arxiv.org/abs/1308.4008v1

The scope of this issue is parallel implementation using CUDA in the cuda layer.

Important: remember to modify the solution folder structure according to the modifications done in #6 - #7 (create bench folder and namespace).