Remove unnecessary and incorrect code that tried
to pull delimiter commands out of the middle of
statements.

client/mysql.cc:
  Remove unnecessary and incorrect code that tried
  to pull delimiter commands out of the middle of
  statements.
mysql-test/r/mysql.result:
  show we no longer parse DELIMITER when
  we shouldn't.
mysql-test/t/mysql_delimiter.sql:
  show we no longer parse DELIMITER when
  we shouldn't.