Extract the error messages into a better configuration file

[jwir3]

Right now, our configuration file is pretty lame. We have a bunch of defaults all over the place. Instead of this, we should put all of our error messages into a .JSON file, that is first searched for in the current usage directory, then in the package directory. It should be in the following form, and be baked into the web build of the application:

{
  "errorMessages": {
    "validation": {
      "password": {
        <CAUSE> : <MESSAGE>
      }
    }
  }
}