WL#1481: Add all test from grant.pl to mysql-test-run

Affects: Server-4.1   —   Status: Un-Assigned   —   Priority: Medium

Add all test from tests/grant.pl to mysql-test-run

This may require some modifications to client/mysqltest

Note that this test should only be allowed to run with a local server as we have
to ensure that we don't drop all users from a production database.

After this is done, we can delete grant.pl and grant.res