[FIX] race condition for test cursors
If a test ends before handling all its http queries (serialised by a Rlock),
threads created for unfufilled queries may hang because the interrupted thread
might not have unlocked its cursor as it might have dissapeared from
HTTP_SESSION before request release_test_cursor. We now use the cursor itself
instead of HTTP_SESSION.
Merge branch 'master' of bzr::lp:openobject-server