Edit metadata dialog: Improve performance by only writing changed fields to the databse when clicking OK or Next

Edit metadata dialog: Do not auto change the title sort field when
clicking OK if the title was changed. Instead the title sort field must
be changed explicitly.
Edit metadata dialog: If the title's case is changed auto-update the title sort
Book details panel: Make series and tags clickable. Clicking on them will search the calibre library for all books in the same series/ having the same tag

Fixes #1341297 [[Enhancement] make series name (in book details) a link/clickable](https://bugs.launchpad.net/calibre/+bug/1341297)
Fix searches on Yes/No columns using the terms ('blank', 'checked', 'unchecked') not working on non-English calibre installs