Upgrade django-cache-machine to 0.8 (bug 883477)

count()s caching is disabled in tests, this was already done before
by accident, this is now done on purpose because it messes up with
all the tests.
Invert the `reindex` settings check.

This command no longer touches Marketplace and doesn't need the
Marketplace settings.
Make --wipe a bit less drastic (bug 805036)
Optionally reindex AMO stats, defaulting off.

Indexing the AMO stats takes a very long time. When we only need to
reindex AMO this adds a lot of delay.
Commit from Mozilla Verbatim by user hyeonseok@gmail.com.: 5144 of 5453 strings translated (0 fuzzy).
Added Hungarian to languages (bug 923930)
Updated STATIC_URL to end with a slash as requested by Django
update flash; bug 922791
Merge pull request #1224 from diox/upgrade-cache-machine-0.8

Upgrade django-cache-machine to 0.8 (bug 883477)
Remove specific cache_key implementation for Translations to unbreak tests

The default from CachingMixin is fine, and actually better because it uses
.pk instead of .id. The real magic is in self._cache_key().