- Using QPrintDialog with QPrinter settings             almost DONE
- FIX custom layout icon                                almost DONE
- add tool tips                                         some
- add an attribute for desktop file
- add Atckin's layout to p.a.
- fix UIs                                               some
- first assistant page should be a choice between 
  "one photo per page"   aka p.i.
  "more photos per page" aka p.a.
- clean code
- evaluate if removing p.i. after merging.

Found QT odd behaviors
- QPageSetupDialog::open does not set QPrinter correctly (Unix?) -> used exec
- QPrinter Custom page size (HP CUPS settings) is restored as custom 0,0
- QPrintDialog(Qprinter*) does not care QPrinter margins if OutputFormat
  is set as PdfFormat or PostScriptFormat
- QPrinterInfo::availablePrinters() seems to be usefull for PageSizes
  only for default in case of printers :(
