Split MxArray out of bridge into standalone file. Does not depend on bridge. Working to make it API complete with respect to mxArray, but with better calling syntax

Now builds all functions except those dependent on Features2d. Improved build detection if cmake is rerun

input/output assignment in templates is working for non-trivial cases. Updated parse_tree to handle '/IO' and '/S' modifiers

Started handling trivial case of return references. Removed most modules from build tree while testing (cmake/OpenCVModule)