The NodeEvaluation makes it difficult to use a course node in the
learning path access concept. So it is refactored to a minimum extent,
so that it can covering the previous functionality.
As a replacement a new security callback and a new tree node type is
introduced.

organization, implement segment view for user visit card to better
inline in user management, implements several features for all roles
(allow enrollment, mandatory confirmation email by enrollment, allow
autocomplete, bulk changes...), add roles like lecture manager, quality
manager..., enhance the roles editor in user management

OO-2043: add message under the toolbar is a course is freezed, better handler changes of status, reload course element by status changes...

OO-1499: delete export folder after the import of a course, upgrade task which delete these folders on current courses

OO-990: rework importation of course node with references, implement autowiring capabilities in controllers

--HG--
branch : bps