add stem delete function (gsh?)

add a method in gsh which deletes a stem and all subgroups etc... I think it should print out what it will do, and have a dry run mode... here is some GSH that might be a workaround...

addRootStem("a", "a");
addGroup("a", "groupA", "groupA");
addStem("a", "b", "b");
addGroup("a:b", "groupB", "groupB");
addStem("a", "c", "c");
addGroup("a:b", "groupB1", "groupB1");
addGroup("a:c", "groupC1", "groupC1");
addGroup("a:c", "groupC2", "groupC2");

grouperSession = GrouperSession.startRootSession();

stem = StemFinder.findByName(grouperSession, "a");
for(child : stem.getChildGroups(Stem.Scope.SUB))

{ System.out.println("deleting: " + child.getName()); child.delete(); }

stemList = new ArrayList(stem.getChildStems(Stem.Scope.SUB));
Collections.sort(stemList);
Collections.reverse(stemList);
for(childStem : stemList)

{ System.out.println("deleting: " + childStem.getName()); childStem.delete(); }

stem.delete();

StemFinder.findByName(grouperSession, "a");