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).
* 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.