OO-662: optimize the members view of course and group. I make three queries to prevent to attack with the o_bs_membership, and prevent a cross product

OO-662: better performance on login for large instance with these portlets on: courses for students, courses for teachers, groups

OO-623: add fields for managed groups and repository entries, add a lifecycle DB object, enhance the REST API to search with externalId/externalRef...

OO-399: fix a backwards compatibility check in the mail course building block, fix the query for the fallback based on group names

OO-291: fix load for update for PostgreSQL, fix unit test for course group management (always consume entity before queriying the database!), fix the statistics rights in the course view

OO-291: optimize synching with instant messaging in the case of batch update, fix rights for the lin links statistics and course db in course...

OO-291: show all membership per group in the list not only one, translation and wording in english and german, fix the group's home page and the mebers panel, show the waiting list, don't show inexistent panels...

OO-291:  enhance the main search function for groups, add search in waiting list, add search of public group, add unit tests