+ fix crash in spnav settings dialog while changing language, improve whitespaces
+ when creating picture check whether pbuffer is supported
use 4 spaces to indent XML output
use ISO 8601 timestamps including timezone

for creation and last changed properties
+ utc time with timezone
 + implement PrefQuantitySpinBox
+ fixes #0001849: Enable Spin Boxes support for Pad, Fillet and Chamfer
Draft: small fix in Draft.py