Simple JDBC Authority connector

For scenarios when privileges are based on SQL database with user records and some authorization tokens assigned to them (groups, etc).
It could help when you have to index number of www sites based on common user-group authorization in database. Also it could help on showcases, presentations and demo versions of "solr-manifold-search client" to show how authorization works.

(of course I already have this connector written as additional class in default JDBC connector so I could use some of its classes )