In the process of moving Http into its own module (#2680), there is still a requirement to depend on angular2 because of facades and dependency injection. The facades should be moved into their own top-level package so that other top-level modules will not need to depend on all of Angular2.

Right now, I'm planning to take this on after I finish #2680, since the process will be fresh in my head. But I'm waiting to self-assign until I clear some things off my plate.