Guard against missing .boardTitle

And realign/cleanup onready.co things.
Move Post/Thread templates to separate files

Gonna see if I can eliminate the post and thread classes entirely. OOP
is for losers.
Munge forcequotes before rendering body

Hmm, it doesn't look like it changed the rendering speed much. I had
thought that body attachment would trigger rendering once, then all the
DOM manipulation for forcequotes would be batched into an additional
reflow, so munging at prerender would be faster. I'm only on a tiny
thread though, so maybe I'll notice the difference more later.
Refactor backlinks to single source file

_much_ better factoring. Got rid of a few bugs in the process, I think.

Not sure if the backlinking is now slower, because netbook. I do scan
for backlinks on every postinsert now though, which is unnecessary for
previews/inlines. Gotta get rid of that still.

The Post class is significantly smaller, yay! just need to tease out
Post[id] usage now.