- removed tr1 usage (dropped in C++17)
- moved includes of vector/map/iostream/limits into ts.hpp
- require opencv_test + anonymous namespace (added compile check)
- fixed norm() usage (must be from cvtest::norm for checks) and other conflict functions
- added missing license headers

* MulSpectrums
* StereoConstantSpaceBP
* BruteForceNonLocalMeans

* remove overloads with explicit buffer, now BufferPool is used
* added async versions for all reduce functions