CAY-1977 | Remove "DbEntity Already Exists" dialog
Merge remote-tracking branch 'upstream/master' into CAY-1977_1

Conflicts:
	cayenne-server/src/main/java/org/apache/cayenne/access/DbLoader.java
	modeler/cayenne-modeler/src/main/java/org/apache/cayenne/modeler/dialog/db/DbLoaderHelper.java