This patch includes following changes and new features:
* Group sync in enrol_cohort plugin.
* Option for editing of role in existing cohort sync instance.
* Group memberships are now restored after enrolments.
* New enrol method for restore of protected group membership.
* New component callback 'restore_group_member' for restore of general plugin group membership.
* New component callback 'restore_role_assignment' for restore of general plugin role assignments.
* Implemented group membership protection in enrolment UI.
* Other minor fixes and cleanup.
Notes:
* The YUI base enrolment page is not reimplemented yet - see MDL-35618.
Includes option to convert all enrolments to enrol_manual instances, support for mapping of custom fields and fixes for several other problems. This does not include support for custom enrol tables, it will be addressed in another issue.
Refactoring and improvements of the accesslib.php library including prevention of access for not-logged-in users when forcelogin enabled, improved context caching, OOP refactoring of contexts, fixed context loading, deduplication of role definitions in user sessions, installation improvements, decoupling of enrolment checking from capability loading, added detection of deleted and non-existent users in has_capability(), new function accesslib test, auth and enrol upgrade notes.
More details are available in tracker subtasks.
New PARAM_COMPONENT, PARAM_AREA and PARAM_PLUGIN + fixing of hopefully all current incorrect parameter types. This should help with diagnosing of incorrectly named 3rd party plugins too.
As part of this patch I also introduced a new method in accesslib can_access_course that can be used
to check a users access to a course.
I also fixed a minor issue with guest access flag caching in require_login
* fixed order of deleting in course adn context
* adding course context to event data because it is not available alter and some stuff may depend on old context id
* adding option for context purging (keeps the context record because it might be still referenced later and it would be recreated)
* new course enrol cleanup
* removing content from some course fields that were referencing deleted content
* coding style and phpdocs improvements
