Fix ShapeObj::label not being virtual.
Fixes for dashed connector strokes.

Old code was reversing and closing the connector path for drawing,
messing up drawing of dashed paths (which was referred to as dotted in
code).  This is now fixed.  Also the property can now be accessed via the
Q_PROPERTY system.
Restore dock widget state & geometry when launching.
Merge remote-tracking branch 'upstream/master'