[multi-sources-removal] drop repository entities_modified_since public api
actually only used by pyrorql/zmqrql sources which have been dropped.
This will allow to drop a bunch of system meta-data (eg deleted_entities)
Related to #2919300
.. winclude:: search_sample_queries
You can as well type complex queries using the RQL_ query language,
used every where to build dynamic pages of this site.
You can use one of the following prefixes to specify which kind of search you
want:
* `rql` : RQL query
* `text` : full text search
.. _RQL: doc/tut_rql