Generating parts crashes if score contains a text frame

Windows 7, GIT commit: 6dffde5

1) create score for two instruments
2) add a text frame (not a vertical frame containing text - and actual text frame)
3) add text
4) File / Parts
5) New All
6) OK

Result: crash

Cause is obvious - missing handling for TBOX in excerpt.cpp. Fix forthcoming, although I won't be surprised if there aren't more places this "new" frame type is not handled.