Not replicating the mysql database *at all* any more. All changes to
mysql tables are replicated by replicating the statements that do
the changes.


mysql-test/r/rpl_do_grant.result:
  Result change
mysql-test/t/rpl_do_grant.test:
  Deleting grants on both master and server since the mysql
  database is not replicated any more.
sql/handler.cc:
  Removing code that selectively checks what tables in the mysql
  database to ignore. The entire mysql database is not replicated
  any more.
sql/log_event.cc:
  Disabling code to reload grants and access when certain tables are
  touched.
sql/rpl_rli.h:
  Removing unused code.
sql/slave.cc:
  Removing unused code.
sql/sql_class.cc:
  Mysql queries (i.e., queries that affects tables in the mysql database)
  are now replicated by statement instead of replicating the tables in
  the mysql database.