Extend API so we can control if exceptions are raises (in UI mode we need a way without catching exceptions in ZODB scripts to detect and inform user that there's a problem with his URL)

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@35725 20353a03-c40f-0410-a6d1-a30d3c3de9de