Support for COMMIT/ROLLBACK optional arguments


innobase/include/trx0roll.h:
  WL#1967
    trx_release_savepoint_for_mysql()
innobase/trx/trx0roll.c:
  WL#1967
    trx_release_savepoint_for_mysql()
mysql-test/r/innodb.result:
  WL#1967
    Test for savepoint release
mysql-test/t/innodb.test:
  WL#1967
    Test for savepoint release
sql/ha_innodb.cc:
  WL#1967
    innobase_release_savepoint_name()
sql/ha_innodb.h:
  WL#1967
    innobase_release_savepoint_name()
sql/handler.cc:
  WL#1967
    ha_release_savepoint_name()
sql/handler.h:
  WL#1967
    ha_release_savepoint_name()
sql/lex.h:
  WL#1967
    New tokens: CHAIN, RELEASE
sql/mysqld.cc:
  WL#1967
    new option: completion-type
sql/set_var.cc:
  WL#1967
    new option: completion-type
sql/sql_class.h:
  WL#1967
    new option: completion-type
sql/sql_lex.h:
  WL#1967
    Support RELEASE SAVEPOINT
    additional flags to support COMMIT/ROLLBACK options
sql/sql_parse.cc:
  WL#1967
    Transaction operations in mysql_endtrans(), begin_trans()
sql/sql_yacc.yy:
  WL#1967
    Support COMMIT/ROLLBACK optional args