Parse intro messages

https://www.wikidata.org/wiki/Special:SetAliases shows a plain
<code>|<code>


UNTESTED patch


Switched to rawElement, which should be safe as the message is
fully parsed.

Not sure if this message really belong inside the form box, it
seems a little odd. Perhaps we should use a better layout so we
don't have to add this message.

Change-Id: I972e86d576d4525f6c76cdf8de4c7c5f55fdece5
Merge "Parse intro messages"