New worklist cache behaviour to avoid problems when alarm and users were triggering a refresh in parallel:
- only the alarm can trigger a worklist refresh
- refreshing uses DELETE/INSERT instead of DROP/CREATE/INSERT.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@25038 20353a03-c40f-0410-a6d1-a30d3c3de9de