DateFilter: fix react focus warning on missing ref
DateFilter: fix react focus warning on missing ref

+ code tidy up

rafmsou/keystone,Pop-Code/keystone,dvdcastro/keystone,trentmillar/keystone,Yaska/keystone,concoursbyappointment/keystoneRedux,ONode/keystone,cermati/keystone,dvdcastro/keystone,frontyard/keystone,andrewlinfoot/keystone,andrewlinfoot/keystone,pr1ntr/keystone,xyzteam2016/keystone,dryna/keystone-twoje-urodziny,pr1ntr/keystone,sendyhalim/keystone,Adam14Four/keystone,matthewstyers/keystone,cermati/keystone,vokal/keystone,jacargentina/keystone,jacargentina/keystone,linhanyang/keystone,ratecity/keystone,sendyhalim/keystone,dryna/keystone-twoje-urodziny,matthewstyers/keystone,frontyard/keystone,trentmillar/keystone,snowkeeper/keystone,snowkeeper/keystone,benkroeger/keystone,frontyard/keystone,rafmsou/keystone,trentmillar/keystone,matthewstyers/keystone,w01fgang/keystone,vokal/keystone,concoursbyappointment/keystoneRedux,naustudio/keystone,danielmahon/keystone,brianjd/keystone,Pop-Code/keystone,michaelerobertsjr/keystone,jstockwin/keystone,michaelerobertsjr/keystone,benkroeger/keystone,brianjd/keystone,matthieugayon/keystone,Yaska/keystone,alobodig/keystone,benkroeger/keystone,jstockwin/keystone,w01fgang/keystone,Adam14Four/keystone,naustudio/keystone,ratecity/keystone,alobodig/keystone,danielmahon/keystone,vokal/keystone,ONode/keystone,danielmahon/keystone,xyzteam2016/keystone,Yaska/keystone,matthieugayon/keystone,andrewlinfoot/keystone,naustudio/keystone