This patch makes it so that querystrings are no longer considered part of a mojo application's identity.

So if you connect to http://a?foo, then http://a?bar, you'll end up talking to the same application, just two different connections.

The URL of each connection is sent to the app via a new param in AcceptConnection().

This patch also adds some app tests that exercise http app loading, which wasn't tested before.

R=qsr@chromium.org

Review URL: https://codereview.chromium.org/943053003