Expose Python DB API 2.0 exceptions and escape_string() to the clients so that they can use and import them from here.  Retry more safely the establishing of the database connection in case the database is down. (BTW, note that this version of persistence database connectivity is not thread-safe, we should replace it with the thread-friendly connection pool technique in the future.)
Expose Python DB API 2.0 exceptions and escape_string() to the clients
so that they can use and import them from here.  Retry more safely the
establishing of the database connection in case the database is down.
(BTW, note that this version of persistence database connectivity is
not thread-safe, we should replace it with the thread-friendly
connection pool technique in the future.)

tiborsimko/invenio,tiborsimko/invenio,inveniosoftware/invenio,inveniosoftware/invenio