hosted readme out of date

[devoncarew]

The readme on pub.dartlang.org lists the repo url as github.com/dart-lang/route - it's since moved to https://github.com/justinfagnani/route.

Additionally - if this library has been deprecated in favor of route_hierarchical - the readme should be updated to that effect in order to save time for people looking for routing libraries. I'm not sure if that's the case (but this library hasn't been updated since Nov 2013).