clientError and serverError exit after they're done so no need for
break or return. Also, $this->format is default.
We also got rid of the incredibly verbose version of $this->isPost()
which was spread all over the place.
Not all of this cleaning up is done yet.
I implemented changes from quitter.se's new API that their front-end qvitter
uses, https://github.com/hannesmannerheim/qvitter/blob/master/api-changes-1.1.1/CHANGES
However I left out the URL shortening commens, since I believe whatever behaviour
they experienced that caused them to implement this was a bug (or many) and should
be fixed in their proper areas and that shortening should not be entirely left
out in API calls.
L10n/i18n updates.
Superfluous whitespace removed.
Add FIXME for a few i18n issues I couldn't solve this quickly.
Takes care of documentation for all core code added in merge of "people tags" feature (Commit:e75c9988ebe33822e493ac225859bc593ff9b855).
