Update segmentation.cpp

Added detailed comments to watershed()
Update segmentation.cpp

removed trailing whitespaces
Implement VideoCapture::get, CvCapture::getProperty, IVideoCapture::getProperty as constant methods.
fix crash when sample point out of image boundaries
install test data on Windows platform too
move allocMatFromBuf function to farneback.cpp:

* it is the only place, where it is used
* no need to make this function public
rename CudaMem -> HostMem to better reflect its purpose
move CUDA core tests to core module
add more FeatureSet constants
add cuda::HostMem::getAllocator method

it allows to use cudaHostAlloc methods for cv::Mat objects
add Allocator parameter to cudev::GpuMat_ contructors
refactor CV_CUDA_TEST_MAIN, use CV_TEST_MAIN for it

use CV_CUDA_TEST_MAIN for opencv_test_core to initialize CUDA
device information
fix GpuMat::swap method:

add swap instruction for allocator field
Added enviroment search paths for OpenNI2 for linux and fixed specific warning
rewrite cuda::cvtColor with new device layer and fix test failures
fix cuda match template:

use correct types for integral/sum outputs
fix tests for match template
disable sanity test for GeneralizedHoughGuil

the algorithm is not stable yet
improve error reporting in _InputArray methods
disable GeneralizedHoughGuil performance test