Made routes compiler its own plugin

* Improved the structure of routes compilation, so that it's more configurable
* Made the incremental compilation good
* Took many of the old integration tests for the router and turned it into a scripted test
* Wrote scripted tests for incremental compilation
* Included mocha tests for the JavaScript reverse router in incremental compilation

Not really, because the tests, which run assertions on the scala-2.11 path, would break if you changed it to 2.10.  That's why I set it explicitly here.