Fix MdbViewer s.t. it doesn't hang on Pdb/TablePicture.
Get cropping to work easily.
Crop & Zoom
Viewer:
1) Add Zoom
2) Add drag & scroll with hand
3) Crop
a) when actual size, it works!
b) when not...
if cropped, use new values for crop width and height.
Be able to save to DB!
