Stop using Express' bodyParser middleware.

The bodyParser middleware is problematic/exploit-prone, and will
be removed in future versions of Express/connect. Since meatspace
has no file uploads anyway, this patch takes the simplest approach
of replacing it with the json and urlencoded middleware.

See http://andrewkelley.me/post/do-not-use-bodyparser-with-express-js.html
Merge pull request #140 from tec27/no_bodyparser

Stop using Express' bodyParser middleware.