Beta build 7

- Behaviour of black level changed. Dark areas have less colour noise now and they don't get a red cast from increasing the level.

- Olympus E-510 recalibrated slightly. (Note: These changes will modify the appearance of previously adjusted pictures. This is something I will try to avoid doing once Scarab Darkroom  is no longer beta.)

- Changed something wxWidgets related, that might fix the collapsed tab at startup bug, which a few people reported.