- QPrinter constructor is expensive, particularly on systems where this triggers
a network scan for available printers. We definitely don't want to do this on
every ApplicationWindow initialization (i.e., application start, new project
and open project) just to get a default export resolution. Having this depend
on the settings of the printer that happens to be default /on the first
application start/ (value will be taken from settings subsequently) is insane
anyway, regardless of performance penalty.
=> changed to hard-coded default of 72 dpi
