Change route logic to redirect to module-specific URL

We now redirect to module specific route (either setup or auth) depending on whether a user account exists or not.  After redirect, a module should take over and handle this request.  This also requires adding new module-specific routes (see password route in server-config.js).

@krulwich, @suprbh, @ceg1236 
We could do it either way. The reason I initially made it async is because its doing a read from the file system, which might take time. I could just as easily use fs.readFileSync for that. However it seems like another option would be to pass the response along to the module method, instead of having the module's render method return html, which would allow the module's method to handle the GET request however it wanted to. Then the controller wouldn't be making any assumptions about what the module was doing.