[migration] cwunique constraint schema fix must be done in bootstrap migration

[i18n] missing some english translation

we must check constraint for all concerned entities and not stop at the first deleted one

avoid creating a new instance of CleanupDeletedEidsCacheOp if nothing was deleted

[css] fix popup css (login box) for IE7

[user form] use InOutWidget to edit CWUser in_group relation

[widgets, js] add a InOutWidget for multiple select

improve massive deletion performance change hooks.integrity._DelayedDeleteOp implementation to give it a chance of processing the entities by chunks of reasonnable size (500 entities at a time) adapt ssplanner.DeleteEntitiesStep to call a variant of glob_delete_entity with several entities. That variant calls all the before_delete_entities hooks in one go, then performs the deletion, and then calls all the after_delete_entities hooks. The deletion is performed by grouping together entities by etype and by source. adapt the HooksManager to call the hooks on a list of entities instead of on a single entity. adapt the sources to be able to delete several entities of the same etype at once. changed the source fti_(un)index_entity methods to fti_(un)index_entities taking a collection of entities.

[ldap] remove useless hack in unittest_ldapuser.py

[tests] make ldap source test run its own local (Open)LDAP server