This fixes an issue where if one document was imported with a different
DPI than the current one, any document created thereafter would have
this same value (which could then cause problems if a PDF was added to
that new document).
Saving this value to UBDocumentProxy not only makes more sense, it also
fixes this issue.
The documents' metadata.rdf file is now persisted only when a scene in
the document is also persisted; as well as when the document is modified
(trashed / path changed) in the the Documents pane.
Code was cleaned-up a bit too (added a forgotten return value, etc)
Clément Fauconnier
Craig Watson
Claudio Valerio
Luca Capello
Anatoly Mihalchenko
shibakaneki
Claudio Valerio