The rbext tool had a couple of problems when trying to run an

extension's test suite, now that we've updated to the newer version of

Django. The first of these was that apps were not getting initialized

properly before attempting to discover tests; this has been fixed by

adding a call to reviewboard.initialize(). The second was an error

attempting to use Review Board's collectstatic. Extension test suites

shouldn't need this, so I've turned off the collect step from rbext.

Was able to use rbext test -m ... for a couple different extensions.