enable training test. refactor globbing
use OpenCV's twister.
Merge pull request #643 from cuda-geek:refactor-softcascade-globbing
Main module headers are moved 1 level up

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

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