CAS integration

See https://drupal.org/comment/8244725#comment-8244725 for a solution for this that uses Feeds and CAS.

Using locations.inc as a template, I put this together. Should be placed in the supported folder as cas.inc.

It adds a "CAS username" value to the mapping dropdown, and uses the cas_user_update function from the CAS module to update the CAS username field.

I can't promise it's the best code I've written -- my last Drupal development was with Drupal 5.x -- but it seems to work in our Druapl 7 environment.

Support for fields from contributed projects should be done by implementing hook_field_user_import_supported_alter() in the project that implements the field, not by adding bloat to this project.

It has been five years. Closing as outdated.