(per Monty's patch).
Remove references to the "COMMENT" field.
WL#2414


mysql-test/r/federated.result:
  alter from "COMMENT=" to "CONNECTION="
mysql-test/r/federated_archive.result:
  change "COMMENT=" to "CONNECTION="
mysql-test/t/federated.test:
  change from "COMMENT=" to "CONNECTION="
mysql-test/t/federated_archive.test:
  change from "COMMENT=" to "CONNECTION="
sql/ha_federated.cc:
  Change parsing of char* table->s->comment to LEX_STRING table->s->connect_string
  (per Monty's patch)
sql/handler.h:
  added LEX_STRING "connection_string"
  (per Monty's patch)
sql/sql_yacc.yy:
  added setting of "connect_string" string and length
sql/table.cc:
  Modifying frm file to store connecting information (code change came from Monty).
sql/table.h:
  added connect_string
sql/unireg.cc:
  Storing information on connection_string (code came from Monty).