[repo] more efficient eid cache operations handling based on set_operation; refactor * split CleanupEidTypeCache operation into one operation for deleted eids and another for added eids, and put them in cw.server.hook * for consistency, move fti unindexing handling from the repository to the system source * handling of deleted eids is done in plan execution (ssplanner), no needs to redo it in *delete_info -> no more need for _prepare_delete_info method, killed

"""Common subpackage of cubicweb : defines library functions used both on the
hg stserver side and on the client side

:organization: Logilab
:copyright: 2001-2010 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.
:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr
:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses
"""