I've tagged 0.27_rc0 and uploaded it to Debian experimental.
For the next week or so I'll take NEWS updates and bugfixes for 0.27.

The following changes might need a NEWS item, please send patches to
NEWS for your changes

Antoine Amarilli (1):
      doc: create manpage folders with right permissions

Daniel Kahn Gillmor (15):
      cli/insert: add --world-readable flag
      doc: Examples of notmuch-reindex use and crypto policy
      lib: expose notmuch_message_get_database()
      properties: add notmuch_message_count_properties
      lib: make notmuch_message_get_database() take a const notmuch_message_t*
      cli: write session keys to database, if asked to do so
      cli/show: reindex when we learned new session keys about a message
      cli/show: enable --decrypt=stash

David Bremner (45):
      doc: add a section on quoting to notmuch-search-terms(7)
      lib: add thread subqueries.
      bindings: clean extra file created by ruby extension build system
      CLI/new: add full-scan option
      configure: check for makeinfo and install-info
      doc: install build and install info pages

Matthew Lear (1):
      Clarify the syntax required when searching using timestamps.

Ruben Pollan (1):
      python: add bindings for notmuch_message_get_propert(y/ies)

Thomas Schneider (1):
      build: Allow user to specify ruby executable