Implemented user search in Join Request modal

classes/CallbackHandler.php

classes/DAO.php

classes/Identity.php

classes/MySQLDAO.php

classes/SessionData.php

classes/TokenHandler.php

classes/UserSearchResult.php

classes/Util.php

config.ini

config.php

css/chosen.min.css

css/style.css

img/ia2-logo-60x60.png

img/logo-ia2-small.png

img/rap-background.jpg

include/footer.php

include/front-controller.php

include/gui-backend.php

include/header.php

include/init.php