Add glob support to tests/runtests.py

[Johannes Dollinger]

Glob support for the app labels passed to runtests.py:

$ python tests/runtests.py "m2*"
Selected 9 tests: m2m_and_m2o, m2m_intermediary, m2m_multiple, m2m_recursive, m2m_through, m2o_recursive, m2o_recursive2, m2m_regress, m2m_through_regress
----------------------------------------------------------------------
Ran 9 tests in 0.823s

OK
$ python tests/runtests.py basic "m2*"
Selected 10 tests: basic, m2m_and_m2o, m2m_intermediary, m2m_multiple, m2m_recursive, m2m_through, m2o_recursive, m2o_recursive2, m2m_regress, 
m2m_through_regress
----------------------------------------------------------------------
Ran 10 tests in 0.849s

OK
$ python tests/runtests.py "modeltests/*"
Selected 56 tests: aggregation, basic, choices, custom_columns, custom_managers, custom_methods, custom_pk, defer, delete, empty, expressions, 
field_defaults, field_subclassing, files, fixtures, force_insert_update, generic_relations, get_latest, get_object_or_404, get_or_create, 
invalid_models, lookup, m2m_and_m2o, m2m_intermediary, m2m_multiple, m2m_recursive, m2m_through, m2o_recursive, m2o_recursive2, many_to_many, 
many_to_one, many_to_one_null, model_forms, model_formsets, model_inheritance, mutually_referential, on_delete, one_to_one, or_lookups, 
order_with_respect_to, ordering, pagination, properties, proxy_models, reserved_names, reverse_lookup, save_delete_hooks, select_related, 
serializers, signals, str, test_client, transactions, unmanaged_models, update, user_commands
----------------------------------------------------------------------
Ran 99 tests in 22.371s

OK
$ python tests/runtests.py "modeltests/m*" templates "custom*"
Selected 21 tests: m2m_and_m2o, m2m_intermediary, m2m_multiple, m2m_recursive, m2m_through, m2o_recursive, m2o_recursive2, many_to_many, 
many_to_one, many_to_one_null, model_forms, model_formsets, model_inheritance, mutually_referential, templates, custom_columns, 
custom_managers, custom_methods, custom_pk, custom_columns_regress, custom_managers_regress
----------------------------------------------------------------------
Ran 35 tests in 2.151s

OK
$ 

Of course this doesn't have to be in runtests.py. But I really like my wrapper script, so here's a patch.