Edit Book: Fix close event geenrated by window system not saving state
Edit Book: Make the warning dialog that pops up when you try to quit while the editor is saving changes in the background a little more clear. Fixes #1347171 [Background save dialog confusion with "save changes"](https://bugs.launchpad.net/calibre/+bug/1347171)
calibredb: When listing formats of a book if there are multiple formats, separate the individual formats with the colon instead of the comma as commas can occur in filenames
Book details panel: Automatically convert ISSN identifiers into links to the periodicals page on worldcat.org.
calibredb list: Do not output extra whitespace+separator after the last field
calibredb list: Add a --for-machine option that causes the output to be made in a form more easily parsed programmatically (it uses ASCII field and record separators)
Fix published date not being merged when merging book records
typo that prevented an optimization to PDF metadata update when nothing changed
Update manual text to match new button layout