- 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

changed hog to work with variable parameters and changed the hog sample to test it with more options

added comments and tests

use abstract interface with hidden implementation