Looks like we don't actually use them; when creating precompiled headers
with Visual C++, a dummy .cpp is created at build time.

adding/tuning multiple run for perf tests failing due to big deviation (functions using TBB can work so)

Also cv::, cv::gpu:: and cv::ocl:: namespace prefixes can be safely omitted
inside CV_ENUM and CV_FLAGS

e.g. <opencv2/core/core.hpp> become <opencv2/core.hpp>

Also renamed <opencv2/core/opengl_interop.hpp> to <opencv2/core/opengl.hpp>

Made all STL usages explicit to be able automatically find all usages of
particular class or function.

- add syntetic images generation function to ts
- use generated syntetic images

MatInfo_Size_Size.resizeDownLinear
MatInfo_Size_Size.resizeUpLinear
TestWarpPerspectiveNear_t.WarpPerspectiveNear
TestWarpPerspective.WarpPerspective