BS-901
Add an adapter on Pageflow to close formeditor when form is removed

Conflicts:
	bundles/plugins/org.bonitasoft.studio.common.diagram/src/org/bonitasoft/studio/common/gmf/tools/CopyEObjectFeaturesCommand.java
	bundles/plugins/org.bonitasoft.studio.properties/src/org/bonitasoft/studio/properties/sections/forms/FormsUtils.java