Refactor code:

*cu files were moved to cu folder
*solver_helpers, sparse_formats were renamed to SolverHelpers and SparseFormats
*GPUKernels file was created
* GPURBF kernel was moved from GPUSolvers to GPUKernels
Merge branch 'master' of https://github.com/ksirg/pyKMLib

Conflicts:
	svm_gpu_example.py