[Zurich] Show "new category" errors in admin.
[Zurich] Show "new category" errors in admin.

Error handling and changes to the base template were added in f0621930,
so an error would cause the form to reshow in the cobrand, but not
display the errors.

otmezger/fixmystreet,ciudadanointeligente/barriosenaccion,opencorato/barriosenaccion,dracos/fixmystreet,rbgdigital/fixmystreet,appstud/fixmystreet,nditech/fixmystreet,antoinepemeja/fixmystreet,rbgdigital/fixmystreet,dracos/fixmystreet,otmezger/fixmystreet,opencorato/barriosenaccion,mhalden/fixmystreet,nditech/fixmystreet,mhalden/fixmystreet,opencorato/barriosenaccion,dracos/fixmystreet,dracos/fixmystreet,otmezger/fixmystreet,nditech/fixmystreet,antoinepemeja/fixmystreet,altinukshini/lokalizo,antoinepemeja/fixmystreet,mhalden/fixmystreet,antoinepemeja/fixmystreet,altinukshini/lokalizo,altinukshini/lokalizo,appstud/fixmystreet,rbgdigital/fixmystreet,opencorato/barriosenaccion,otmezger/fixmystreet,nditech/fixmystreet,opencorato/barriosenaccion,appstud/fixmystreet,rbgdigital/fixmystreet,antoinepemeja/fixmystreet,dracos/fixmystreet,nditech/fixmystreet,appstud/fixmystreet,opencorato/barriosenaccion,rbgdigital/fixmystreet,antoinepemeja/fixmystreet,altinukshini/lokalizo,ciudadanointeligente/barriosenaccion,rbgdigital/fixmystreet,nditech/fixmystreet,ciudadanointeligente/barriosenaccion,ciudadanointeligente/barriosenaccion,mhalden/fixmystreet,otmezger/fixmystreet,appstud/fixmystreet,nditech/fixmystreet,opencorato/barriosenaccion,appstud/fixmystreet,mhalden/fixmystreet,mhalden/fixmystreet,appstud/fixmystreet,antoinepemeja/fixmystreet,ciudadanointeligente/barriosenaccion,ciudadanointeligente/barriosenaccion,otmezger/fixmystreet,altinukshini/lokalizo,dracos/fixmystreet,ciudadanointeligente/barriosenaccion,altinukshini/lokalizo,otmezger/fixmystreet