Optimize DataView group collapse/expand.
Optimize DataView group collapse/expand.

pandell/SlickGrid,gbark/SlickGrid,msuchoi/Coffee,songyaos/SlickGrid,cjsigler/SGrid,thationothe/SlickGrid,GerHobbelt/SlickGrid,coatue/SlickGrid,varunkumar/slickgrid-mleibman,dbirchak/SlickGrid,helin16/SlickGrid,RobertoMalatesta/SlickGrid,SimplGy/SlickGrid,cheminfo/SlickGrid,zamabraga/SlickGrid,Medisapiens/SlickGrid,lanwan/SlickGrid,chrisghost/X-SlickGrid,trazyn/SlickGrid-mini,doctor41/SlickGrid,ceanota/SlickGrid,matrix1992/SlickGrid,dbirchak/SlickGrid,manju-reddys/SlickGrid,TedDBarr/SlickGrid,dynamicaction/SlickGrid,vinicius5581/SlickGrid,mindmatters/SlickGrid,steelsojka/SlickGrid,codexp/SlickGrid,gofflab/neuron-seq-site,codexp/SlickGrid,gofflab/neuron-seq-site,vinicius5581/SlickGrid,dandy/SlickGrid,pandell/SlickGrid,werture07/SlickGrid,Termato/SlickGrid,msuchoi/Coffee,coatue/SlickGrid,ddomingues/X-SlickGrid,iCoreSolutions/SlickGrid,Termato/SlickGrid,msuchoi/Coffee,jesenko/SlickGrid,yamass/SlickGrid,coatue/SlickGrid,pirasis-l/SlickGrid,lanwan/SlickGrid,msuchoi/Coffee,peaceboy/SlickGrid,priyaaanand/SlickGrid,redabakr/SlickGrid,peaceboy/SlickGrid,GerHobbelt/SlickGrid,matrix1992/SlickGrid,dandy/SlickGrid,doctor41/SlickGrid,mleibman/SlickGrid,ddomingues/X-SlickGrid,coatue-oss/slickgrid2,jiangzhixiao/SlickGrid,jiangzhixiao/SlickGrid,mindmatters/SlickGrid,thationothe/SlickGrid,tradingtechnologies/SlickGrid,6pac/SlickGrid,priyaaanand/SlickGrid,JLynch7/SlickGrid,csgsolutions/SlickGrid,zartata/SlickGrid,cheminfo/SlickGrid,jesenko/SlickGrid,steelsojka/SlickGrid,tradingtechnologies/SlickGrid,SimplGy/SlickGrid,songyaos/SlickGrid,mleibman/SlickGrid,gofflab/neuron-seq-site,GerHobbelt/SlickGrid,dynamicaction/SlickGrid,cheminfo/SlickGrid,redabakr/SlickGrid,6pac/SlickGrid,helin16/SlickGrid,coatue-oss/slickgrid2,zartata/SlickGrid,RobertoMalatesta/SlickGrid,werture07/SlickGrid,TedDBarr/SlickGrid,iCoreSolutions/SlickGrid,csgsolutions/SlickGrid,trazyn/SlickGrid-mini,ceanota/SlickGrid,yamass/SlickGrid,chrisghost/X-SlickGrid,manju-reddys/SlickGrid,zamabraga/SlickGrid,gofflab/neuron-seq-site