1.21.1 (unstable):

* Details: Foreign key ID fields: Add a New button next to 
  the existing Find button.
* Related Choices: Allow the user to specify a sort order.
* libglom:
  - Make libglom 1.22 parallel installable with glom 1.20.
  - Document: Added get_translation_available_locales().
  - Field: Remove unused get_gda_holder_string().
  - Remove unused get_sql_format() methods.
  - DbUtils:: Added get_fields_for_table(), 
    get_fields_for_table_one_field(), get_lookup_fields(), and 
    get_lookup_value()
  - LayoutGroup:
    - Add a 
    remove_field(parent_table_name, table_name, field_name) 
    method overload, deprecating the existing method overloads.
    - Deprecate the old has_field() method and do not use it.
  - Remove unused parameternamegenerator.[h|cc] source files.
* Build:
  - Avoid deprecated glibmm API
(Murray Cumming)