ldapadmin - issue 650

Still in a WIP state, committing prematurely so that I'm able to test
a regression onto 14.01 security-proxy
ldapadmin - issue #650

The mapper between LDAP <-> Java does not take into account user
membership. This ensures that members are correctly mapped before saving
the object to the LDAP tree.
ldapadmin - issue #650

Ensures with the test that the users are still present in the group
after having updated the description.
Merge remote-tracking branch 'mine/issue-650' into mergin-fix-issue650

Conflicts:
	ldapadmin/src/main/java/org/georchestra/ldapadmin/ws/backoffice/groups/GroupsController.java
	ldapadmin/src/test/java/org/georchestra/ldapadmin/ws/backoffice/UsersGroupsControllerTest.java
ldapadmin - deactivating test for issue650

This one is supposed to be run against a real LDAP server.
Merge branch 'mergin-fix-issue650' into ldapadmin_testsuite

Conflicts:
	ldapadmin/src/main/java/org/georchestra/ldapadmin/ws/backoffice/groups/GroupsController.java