a big patch; use special proxy types (Input/OutputArray, Input/OutputArrayOfArrays) for passing in vectors, matrices etc.

minor fixes and refactoring of GPU module

added assertion after all kernels calls

added RGB <-> XYZ color conversion.
gpu morphology minor fix.

added gpu exp, log, magnitude, based on NPP.
updated setTo with new NPP functions.
minor fix in tests and comments.

minor refactoring of GPU module and GPU tests, split arithm and imgproc parts.

added gpu compare version for CMP_NE operation

* tests do not crash without test data
* test files renamed in systematic way
* added Test suffix for test classes names
* ts->printf used instead of some cout

implemented saturate_cast on gpu; updated GpuMat::convertTo implementation with saturate_cast; minor fix of convert_to test

Added implementation of remap on GPU. Minor fixes of convertTo. Added opencv_imgproc to gpu_test dependencies.