[Trunk] Re-opening score with 'Documents Stacked/Side-by-Side' previously enabled and playing causes crash
1. Open score ('bach-bc2' or otherwise).
2. Enable either 'Documents Stacked' or 'Documents Side-by-Side'.
4. Open 'bach-bc2'.
Discussion: It happens to this score, but not others I've tried (both 1.1 and 2.0). Perhaps there's something special.
Using MuseScore 2.0 Nightly Build (5004) - Mac 10.6.8.