It is valid to unindex an object without providing it (eg, an object is indexed but does not exist any more), so make "object" parameter optionnal.
Add a test to check that at least one way to find an object to unindex is given.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@16225 20353a03-c40f-0410-a6d1-a30d3c3de9de