Priority 1 (highest)
-Fix resolution of relative filenames in VOB lists.
-Provide a means to specify video aspect and menu & audio language.
-Suppress Mozilla error dialogs when processing (file not found etc).
+Investigate and fix the crash that occurs after we trigger exit from null_prompt_service.
+Make linking to chapters actually work.
Priority 2
Use ffmpeg instead of mjpegtools to encode menus.
Allow explicit ordering of videos.
Priority 3 (lowest)
+Provide a means to specify menu & audio language.
May need to override default menu navigation actions because dvdauthor seems to cause rather undesirable behaviour when buttons are not arranged in a grid.
For any page with no links, add a "back" link (this raises the issue of localisation, of course).
If a page is too large, split it and add "next" and "previous" links (seems very difficult).