- 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
some mandatory string keys like paths must not be empty. Add the special
default value `<none>` so the CommandLineParser can enforce this and
generate an according error message for us.
requesting a previously undeclared key is most likely an programming
error. e.g. a typo "--unused vs --unsued".
So throw in those cases.
Add an according failure testcase.
