Fix re: and glob: patterns in .hgignore (reported by Brad Schick) relglob: and relre: were already detected for a long time, so I kept this undocumented functionality, especially as it was already tested in test-hgignore.

To run the tests, do:

cd tests/
python run-tests.py

See http://www.selenic.com/mercurial/wiki/index.cgi/WritingTests for
more information on writing tests.