Properly expand cropped inline threads
Properly expand cropped inline threads

If a cropped inline thread is clicked, expand it, but none of its parent
threads (which might also be cropped).  This requires:

- New state variable: didExpandTruncated
- Reset per click state variables when a new click starts
- Don't show a reply form (or, in the future, an inline menu) on a click
  that expands a cropped thread

debiki/debiki-server-old,debiki/debiki-server-old,debiki/debiki-server-old,debiki/debiki-server-old