created gpucodec module for gpu video decoding/encoding
created gpuarithm module for gpu arithmetics operations
created gpufilters module for gpu image filtering
CV_GPU_TEST_MAIN macros
gpunvidia module
fixed build
removed columnSum function (it is a duplicate for reduce)
added private header to gpunvidia module
replaced NCV_EXPORTS with CV_EXPORTS
made objdetect dependecy for gpunvidia optional
moved rectStdDev to gpuarithm
moved copyMakeBorder to gpuarithm module
moved integral to gpuarithm module
removed core dependency
moved mulSpectrums, dft and convolve to gpuarithm
gpuimgproc module