Too many 'skipped' messages in mysql-test-run

[Kristian Nielsen]

When we run mysql-test-run.pl, it spews out a ton of 'skipped' messages:

binlog.binlog_multi_engine [ skipped ] No ndbcluster tests(--skip-ndbcluster)
ndb.loaddata_autocom_ndb [ skipped ] No ndbcluster tests(--skip-ndbcluster)
ndb.ndb_alter_table [ skipped ] No ndbcluster tests(--skip-ndbcluster)
...
rpl.rpl_row_001 'stmt' [ skipped ] Doesn't support --binlog-format='statement'
rpl.rpl_row_001 'mix' [ skipped ] Doesn't support --binlog-format='mixed'
...

These are confusing and annoying. These are tests that can _never_ be run in that
combination due to the way they are written. This is different from tests that are
skipped due to building or running tests in a special way, which can be useful
information that is hidden by this flood of garbage.