added interface + theme options for the end user

interface/web/tools/default-v2_settings.php

interface/web/tools/form/default-v2_settings.tform.php

interface/web/tools/form/interface_settings.tform.php

interface/web/tools/interface_settings.php

interface/web/tools/lib/interface.d/default-v2.menu.php

interface/web/tools/lib/lang/de.lng

interface/web/tools/lib/lang/de_default-v2.lng

interface/web/tools/lib/lang/de_interface.lng

interface/web/tools/lib/lang/en.lng

interface/web/tools/lib/lang/en_default-v2.lng

interface/web/tools/lib/lang/en_interface.lng

interface/web/tools/lib/module.conf.php

interface/web/tools/templates/default-v2_settings.htm

interface/web/tools/templates/interface_settings.htm