Window titles should contain filename (*.pdf) and document title

Currently, window titles in evince contain only the document title of the file displayed. This is inconvenient, because many pdf-files have a title that does not help to identify documents, e.g. files created from Microsoft Word often contain only "Microsoft Word" as title which tells a lot about the creator of the file but nothing about the file itself.

Evince users should not be punished for others people inability to create documents with a title that actually describes the document.

A solution would be to display the filename and the file title as window title, such as "file.pdf: foo bar" or "foo bar (file.pdf)"