Implement new SQL mode - NO_ENGINE_SUBSTITUTION


mysql-test/r/sql_mode.result:
  Test for bug 6877
mysql-test/t/sql_mode.test:
  Test for bug 6877
sql/handler.cc:
  change to ha_checktype()
sql/handler.h:
  change to ha_checktype()
sql/mysql_priv.h:
  new sql mode NO_ENGINE_SUBSTITUTION
  change to args for get_table_type() and create_frm()
sql/mysqld.cc:
  new sql mode NO_ENGINE_SUBSTITUTION
sql/set_var.cc:
  change to ha_checktype() args
sql/sql_delete.cc:
  change to get_table_type() args
sql/sql_rename.cc:
  change to get_table_type() args
sql/sql_table.cc:
  move common code to check_engine()
  change to ha_checktype(), get_table_type() args
sql/table.cc:
  change to ha_checktype(), create_frm(), get_table_type() args
sql/unireg.cc:
  change to create_frm() args