1.5

Removed sessions from Archetypes to avoid ZODB conflicterror,  Backported from: 
- d46bab5c3ba9b0a074de1d3afd8e95600b2de44: Stop using the session_restore_value script. We never create a session in the first place, so looking for one is pointless. 
- 0d0bfab3fc027532f2703499b1c13564a07057bf: Really remove session leftovers