automatically changes curve type to "line"; selecting "no line" changes
curve type to "scatter". A clean solution would require removing either
"no symbol" and "no line" or "line" and "scatter" - not a good idea for a
bugfix release. Closes bug #2231471.
- Fixed setting of attributes for vector plots in PlotDialog.
- Added per mille and per ten thounds signs to SymbolDialog. Closes feature
request #2599846.
