- 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

removed test_precomp.cpp

Added WidgetMerger, Polyline - colors support for each point independently, simple widgets now compute color array instead of setting global color

merged background color with background gradient methods, updated tests to show description of scene