Add body tag to error templates

browser-sync is injecting its script into the top of the body, so it
simply doesn't work if there is no body tag at all.
Refactor wiki pages into controller (p1)

This is just a blind copy-paste to get the code into a more organized
environment. From here we'll start moving some of the logic around and
doing some cleanup.
Refactor wiki pages into controller (p2)

The next step is to clean up the various repeated lines of render code
that react to various errors. We can split the logic into two broad
pieces, one involving the actual logic and the other to render whatever
fell out of the logic.