1.21.6 (unstable):

* Make auto-increment fields work even if they are not primary keys.
  (Murray Cumming) Bug #661702
* Do not hide the database structure if the user does not have view rights,
  and prevent SQL errors in that case.
  (Murray Cumming) Bug #669299
* Allow printing of print layouts from the List view too, to avoid confusion.
  (Murray Cumming) Bug #670462 (alien)
* Print Layout: Avoid sometimes over-scaled images.
  (Murray Cumming) Bug #668901 (alien)
* Users/Groups:
  - Example files: Really load the table privileges.
  - Really prevent changing to developer mode for non-developers.
    Bug #669043 (alien)
  - Allow user and group names to have spaces and other special characters.
    Bug #669012 (alien)
  - Limit user and group name lengths because PostgreSQL seems to have an
    (undocumented) limit.
  - Warn if we cannot get the list of users. Bug #669178 (alien)
  - Add tests.
    (Murray Cumming)
* Button scripts: Check and warn about pygtk2 instead of crashing.
  (Murray Cumming) Bug #669196 (alien) and ##661766 (Andre Klapper) .
* ReportBuilder:
  - Make summary fields work again.
  - Add error checking.
  (Murray Cumming) Bug #669281 (alien)
* Database Preferences: Really store the organization name in the database.
  (Murray Cumming) Bug #668836 (alien)
* Field Formatting: Related Choices: Default to showing the primary key
  (Murray Cumming) Bug #668759#c21 (alien)
* Choices: Allow the field to be be other than the primary key and do not
  crash if it is not, or if it is hidden.
  (Murray Cumming) Bug #668759 (alien).
* Document: Avoid accumulating old nodes in the XML.
  (Murray Cumming)
* Examples: Remove empty group in the Lesson Planner example file.
  (Ben Konrath) Bug #671263
* libglom: Glom::Utils::get_find_where_clause_quick(): Handle an empty value properly.
  (Murray Cumming)
* Use Gtk::Application and Gtk::ApplicationWindow instead of Gtk::Main.
  So far this does not change anything whatosever for the user,
  though --help now doesn't list all options by default.
  (Murray Cumming)  
* Windows build fixes (not complete).
  (Murray Cumming) Bug ##671120 (alien), Bug #670903 (alien)