- problem when altering a table to another engine as the
   table was not removed from the participants.
 - detect the special case of "alter to other engine" in
   ha_ndbcluster::delete_table(), lookup the orignal table name from
   thd and distribute the drop to participants.
 - slightly modify test case as the servers will not be identical after
   alter to other engine
 - remove unused extern in ha_ndb_index_stat.cc
 - enable and fix up ndb_dd_alter, ndb_blob and ndb_partition_range
   which were disabled due to this problem