Factored out common UI code for threshold and connected components filters
Factored out common UI code for threshold and connected components filters

OpenChemistry/tomviz,cryos/tomviz,mathturtle/tomviz,OpenChemistry/tomviz,cjh1/tomviz,cjh1/tomviz,cryos/tomviz,thewtex/tomviz,thewtex/tomviz,cryos/tomviz,thewtex/tomviz,mathturtle/tomviz,OpenChemistry/tomviz,OpenChemistry/tomviz,mathturtle/tomviz,cjh1/tomviz