- Log what is removed, kept and executed before and after BT installation.
- Add 'reinstall' parameter to force reinstallation all items.
  This is useful for special BT that patch upstream objects.
- Add active_process parameter to log into an active process instead of zLOG.
  Also use active_process to track installed item and detect moved objects.
- Use unrestrictedTraverse instead of getattr to access before/after scripts.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@36156 20353a03-c40f-0410-a6d1-a30d3c3de9de