Issue #1422578: Change the signature of the behavior access method to EntityReference_BehaviorHandler::access($field, $instance) for better consistency.

Issue #1422580: Implement CTools class support properly to get automatic autoloading of the class plugins.

Issue #1319040 follow up: update the field's indexes on update, to prevent WSOD when editing an existing field.

This reverts commit 74075a28.

Issue #1340748 by helior and myself: add foreign key information in the field schema for use by various other modules, especially CTools.

Issue #1329354 by Alan D., EvanDonovan: stop using entity_get_info() inside entityreference_field_info(), to avoid unhealthy interactions with other modules.

Issue #1257810: add a new autocomplete mode, that handles multiple values the same way as a nodereference widget.

At this point, the module is feature complete. It provides:

- A generic entity reference field
- Three widgets:
  - Select and Radios/Checkboxes, implemented on top of the List module
  - Autocomplete, implemented separately
- Two formatters:
  - A "label" formatter, with optional link that displays the label of the
    referenced entity (the node title, the user name, etc.)
  - A "entity view" formatter, that renders the references entity using
    a configurable view mode
- Integration with Views
- Integration with Entity Metadta (and as a consequence with Search API and
  the like)

This code comes from various authors, with myself refactoring it.
Special credits to:

- Bojan Zivanovic (http://drupal.org/user/86106)
- Ryan Szrama for the multiple reference fields in Commerce