Create multiple polygons from a contour map

* Fix overwrite of value thresholds
* Fix performance issue with filtered values
* Add "Delete All Polygons" from the polygon collection
* Add area threshold where user can specify area cutoff

ApplicationLibCode/ProjectDataModel/ContourMap/RimStatisticsContourMap.cpp

@@ -44,8 +44,6 @@
 #include "RimEclipseCaseEnsemble.h"
 #include "RimEclipseContourMapProjection.h"
 #include "RimEclipseResultDefinition.h"
-#include "RimOilField.h"
-#include "RimProject.h"
 #include "RimSimWellInViewCollection.h"
 #include "RimStatisticsContourMapProjection.h"
 #include "RimStatisticsContourMapView.h"
@@ -213,8 +211,7 @@ void RimStatisticsContourMap::defineUiOrdering( QString uiConfigName, caf::PdmUi
         if ( m_enableFormationFilter ) formationGrp->add( &m_selectedFormations );
     }
 
-    RimProject* proj = RimProject::current();
-    if ( auto polygonCollection = proj->activeOilField()->polygonCollection().p() )
+    if ( auto polygonCollection = RimTools::polygonCollection() )
     {
         if ( !polygonCollection->allPolygons().empty() )
         {
@@ -389,8 +386,7 @@ QList<caf::PdmOptionItemInfo> RimStatisticsContourMap::calculateValueOptions( co
     }
     else if ( &m_selectedPolygons == fieldNeedingOptions )
     {
-        RimProject* proj = RimProject::current();
-        if ( auto polygonCollection = proj->activeOilField()->polygonCollection().p() )
+        if ( auto polygonCollection = RimTools::polygonCollection() )
         {
             for ( auto p : polygonCollection->allPolygons() )
             {