[repository] deprecate the extid2eid based multi-sources API This API is cumbersome and lead to obfuscated code because of the callback mecanism implied when some entity has to be created. Since we dropped the "true" multi-source, this mecanism is not needed anymore and one should prefer to use the dataimport API inside its parser instead. Notice the cwxml parser will trigger the deprecation warning, it should not be used anymore in favor of ad-hoc parsers.

[ldapfeed] use source's extid2eid, the repo's one will be deprecated in a near future.

[ldapfeed / dataimport] port ldapfeed parser to dataimport API This makes the code easier to understand and will allow to deprecate the old multi-sources api, based on creation callback through repo.extid2eid. Currently with this patch, modification dates are not checked, hence entities will be systematically updated. We run the import with no hooks, because RQLObjectStore can only add entities to the system source.