[BUGFIX] Make default menu behavior use shortcut UID

This changes two things:

1. The default value of `useShortcutUid` is set to TRUE since this will be the desired rendering in almost all cases.
2. The shortcut itself is added to the root line if the current page UID is the target of the shortcut and the shortcut is to "parent of current page".

The result of this is that all shortcuts' active and sub states become properly set when shortcut-to-parent is in used.
Merge pull request #503 from NamelessCoder/useshortcutuid

[BUGFIX] Make default menu behavior use shortcut UID