removed ogl::Texture2D support from InputArray
added CudaMem support to Input/Output arrays
renamed gpu headers (made it more consistent)
removed obsolete DevMem2D class
added Stream support to ogl::Buffer
moved inline implementation to separate file
moved GpuMat implementation to separate file
refactored GpuMat:

* switch to InputArray/OutputArray
* add Stream support
new implementation for GpuMat::setTo (without constant memory)
refactored CudaMem (now alloc type assign only in constructor)
refactored gpu::Stream (minor fixes)
refactored gpu info structures (TargetArchs and DeviceInfo)

now DeviceInfo provides full information about device (from cudaDeviceProp)
restored old header files for source compatibility