- reenable the possibility for SHOW TABLES to delete old files i.e .frm files with .ndb
  where the table does not longer exist in NDB (which can occur in case of initial restart
  or restore from backup).
 - remove hack from ndb_autodiscover3.test
 - remove now unused TNO_NO_DROP_TABLE
 - make Ndb_local_schema::Base push warnings to instead of logging them if used
   from a user thread