#863226 by KarenS, make sure we have a function that will return inactive instances when other instances of the same field are still active.

Revert #780566 by stella, add drupal_alter() for content_allowed_values lists created by userreference and nodereference, needs more thought.

#780566 by stella, add drupal_alter() for content_allowed_values lists created by userreference and nodereference.

- #669800 Do not enforce required attribute for multiple value fields the current user is not allowed to edit.

- #649106 by thekevinday: Fix content_copy_form_alter(), where $form_state argument is not passed by reference.

- #640488 warning: max() [function.max]: Array must contain at least one element in content.module on line 1044.

- #614292 by DeFr - Fix CCK Reference fields based on views broken by recent change in views_plugin_style Views 2.7 (#502348).

- #577590 Prevent validation errors when multigroup is not required and no subgroup of fields if filled in.

- #604830 by mattyoung - 32 characters limit on field and group identifiers in "Manage fields" screen.

- #538458 Do not allow to change the widget type for fields in multigroups when the change is not compatible.

- #551188 "Add another item" for FileField widgets causes Invalid argument supplied for foreach() in content.node_form.inc on line 456.

- #589306 warning: Invalid argument supplied for foreach() in includes/panels/content_types/content_field.inc on line 166.

- #585048 Setting "All users" in "User status that can be referenced" option reverts to "Blocked users".

- #572672 by Jan van Diepen - Remove redundant (and bad) inclusion of node/content_types.inc in content_copy_import_form_submit().

- #558420 Accept trimmed titles in nodereference autocomplete validation to prevent title mismatch errors when title ends with space.

- #558744 by chellomere - Fix one of the swedish translation strings to be correct, and much clearer.

- #550252 by GuyPaddock - content_db_index_exists produces SQL errors when creating node reference fields for MySQL 4 (related to #231453).