Check for duplicated DN on user creation
Implement _preModifyUser on LdapUserBase
Change user modification hook from _modifyUser to _preModifyUser

Throw DataExists exception if the user try to rename a user on a
container and already exists
set proper dependency
Merge branch '3.2' into scabrero/samba-improve-user-creation-errors

Conflicts:
	main/samba/ChangeLog
	main/users/ChangeLog
releasing bwmonitor 3.3.1
releasing common 3.3.1
releasing core 3.3.3
releasing ebackup 3.3.1
releasing firewall 3.3.1
releasing mail 3.3.1
releasing mailfilter 3.3.1
releasing objects 3.3.1
releasing openchange 3.3.1
releasing remoteservices 3.3.1
releasing samba 3.3.1
releasing software 3.3.1
releasing squid 3.3.2
releasing users 3.3.1
Hide internal groups from the Zarafa's global addressbook