Added a Forum

Resolves #498.
Resolves #895.

http://jenkins.buttonweavers.com:8080/job/buttonmen-AdmiralJota/142/

Depends on #862 for hashbang and color support.

@blackshadowshade: I'm guessing glassonion will probably ask you to look at the SQL in this one as well.

@cgolubi1: You'll probably want to pay special attention to ```Env.prepareRawTextForDisplay()```, as this is what now santizes user input for display (for both chat and the forum). We're also putting the raw user input into the ```data-rawPost``` attribute in ```Forum.buildPostRow```. I believe this is safe, but I wanted to give you a heads up anyway. It probably deserves a little extra testing attention.

I assume that as soon as this goes online, there'll be a half dozen new tickets with suggestions for improvements...
What does "nullable" mean?