Fix relative links
Implemented a workaround for when The DataTank instance is not running on a direct path. Fixed all relative links. Removed redundant authentication. Added loading for main.css and the logo in UiResourceController. Added a error message for the authentication form when giving a wrong user/password combination. Fixed a problem with routelist.twig (some variables were not accessible). Fixed an issue with the writing of routes when the remove function was used. Fixed URL matching to allow both .about and the standard URL.