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.

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:e75c9988).

* translator documentation updated.
* superfluous whitespace removed.

* Mostly punctuation updates so that the same message is used consistently in all of StatusNet.
* Some cases of "Title Case" removed, because that does not appear to be used consistently.