1.28.6 (stable):

* Fix crash when loading TIFF or PDF files into an image field,
  caused by assert in recent versions of libevince-view.
  (Murray Cumming) Bug #761396 (m.rick.mac))
* Really forget a table when removing it.
  (Murray Cumming) Bug #754645 (m.rick.mac)
* Table deletion: Actually let the user cancel the dialog.
  (Murray Cumming)
* Initialize PostgresSQL database with the C locale.
  Because using the current locale seems arbitrary and useless to other users.
  (Murray Cumming) Bug #761372 (m.rick.mac)
* Try to catch filesystem errors sooner.
  (Murray Cumming) Bug #761373 (m.rick.mac)
* Details layout: Allow notebooks at top-level.
  (Murray Cumming) Bug #759511 (m.rick.mac)
* Connection to central server:
  - Specify a timeout.
  (Murray Cumming)