Add a useful stacklevel to some RemovedInDjango19Warnings
Skipped a test that errors rather than marked it as an expectedFailure.

The test throws an error which Python 3.4 doesn't seem to catch as an
expectedFailure.

refs 7476d96f83a004d674244aeb7a66289035427396
Fixed a deprecation warning on Python 3.
Fixed #21941 -- Documented the kwargs param of django.conf.urls.url().

Thanks cjerdonek for the report.
Added Python 3.4 support notes.
Fixed a deprecation warning with the HTMLParser safe argument.

refs 6ca6c36f82b97eafeada61384b2e2f1d0587da86
Skipped JavascriptI18nTests if Firefox isn't properly configured.

Code borrowed from django.contrib.admin.tests. Without this, the class can
throw an exception with something like "The browser appears to have exited
before we could connect. The output was: Error: no display specified"
Corrected deprecation warnings.