Reserved IDs may not be released on command cancel

```
The IdHandle class is overly complex and needs to be simplified. One issue 
is that most command dialogs do not return reserved IDs to the pool when 
the user cancels (however, it seems to come back on the next session).
```

Original issue reported on code.google.com by `ola.stan...@gmail.com` on 26 Feb 2009 at 10:00
