Fixing faulty (last) commit
Merge branch 'upgrade'
Merge in 'master'
Introduced notification mechanism, improved sync.

Adapted to run on latest DeepaMehta 4.2-SNAPSHOT.

Changes:
- depends on new dm4-websockets and eduzen-reviews now
- moodle author and license-info are read out and added "Moodle Items"
- added Migration3 introducing a "Score" to "Moodle Items"
- courses must have tags now (set by admin before new course syncs)
  means: before a course will be synced it needs 1 tag set and
  courses can be edited from "admin" by now
- items get implicitly always the hashtag of their course set
- preventing that (ACL-wrong) updates can be triggered manually
- new courses, new sections and changed items send notifications
- items update also if just their name has changed
- fixed int ClassCastException with (moodleTimeStamp * 1000)
- creating (eduzen-)authorship for every moodle-item
- setting ACLs also for (these authorship) associations

Known Issus:
- Hiding/removing (previously not hidden) created moodles items

Documentation:
Currently depends on the necessary capabilitues set, the most basic features activated (REST/JSON) i
and the following functions assigned to a new custo web service:
- 'core_webservice_get_site_info()'
- 'core_enrol_get_users_courses()'
- 'core_course_get_contents()'