NEWS: update

Bump version to 0.9.9.13

mu4e: fix :thread-subject for the non-threaded case

mu4e: update documentation

Bump version to 0.9.10

* bump version to 0.9.9.6

Merge pull request djcb#445 from thierryvolpiatto/master

* mu4e: kill composition buffer when quitting from reply prompt

* bump version to 0.9.9.6pre3

* goes with the previous

* mu4e: do a better job of trying to show images (without delay)