Added fixes to make last_insert_id() to work.


mysql-test/r/federated.result:
  BUG #14768
  
  New test results for last_insert_id()
mysql-test/t/federated.test:
  BUG #14768
  
  Tests for last_insert_id()
sql/ha_federated.cc:
  BUG# 14768
  
  * Added code to set last_insert_id()
  * Added code to free share->scheme
sql/ha_federated.h:
  BUG #14768
  
  New method for setting last_insert_id()