[Trunk] Unable to manually extend objects

1. Create piano score.
2. Apply spacer to a stave.
3. Double-click it.

Result: The little square doesn't appear in order for it to be moved.

Discussion: Likely applies to anything that is manually-extendable (including pedals).

Using MuseScore 2.0 Nightly Build (4801) - Mac 10.6.8.