NGApplication should not be a global

[hugithordarson]

We want to be able to construct the request handling machine that is NGApplication without any side effects.
Essentially, what we want to be able to do is to do something like this:

var app = new NGApplication( properties );
var response = app.dispatchRequest( new NGRequest( .... ) );
assertTrue( response.status() == 200 );

[paulhoadley]

Possibly related: why is a method like isDevelopmentMode() static? Presumably because NGApplication is effectively a singleton, so it may as well be.

[hugithordarson]

isDevelopmentMode() is kind of a relic from Wonder's static version, the reason it being static there that it's used in application initialization, before there's an application instance to invoke anything on (and I've hit the same problem in NGApplication).

It should definitely be a part of the "environment", i.e. properties used for initialization. Ideally I'd want to do away with the globally declared application() (and therefore global properties) altogether.