Merge branch 'release' into develop

CONTRIBUTING.md

@@ -5,6 +5,8 @@ If you have a usage question, please email help-at-mapbox.com.
 
 If you want to contribute code: 
 
-1. If it's generally useful to mapping libraries, consider contributing to the upstream project [Alpstein/route-me](http://github.com/alpstein/route-me), from which this project is derived. We regularly contribute the generally useful parts of our SDK to this project. 
+1. In past, for things that are generally useful to mapping libraries, we encouraged contributions to the upstream project [Alpstein/route-me](http://github.com/alpstein/route-me), from which this project is derived. But that project is no longer active, so you can contribute pull here. 
 
-1. If it's Mapbox-specific, fork and submit a pull request **against the `develop` branch** so that we can review, discuss, and possibly integrate your code. 
+1. Please familiarize yourself with work in [`mapbox-gl-cocoa`](https://github.com/mapbox/mapbox-gl-cocoa), which will eventually be the successor to this codebase. That framework solves lots of problems inherent to a Core Graphics-based framework like this one such as performance and flexibility. 
+
+1. Fork and submit a pull request **against the `develop` branch** so that we can review, discuss, and possibly integrate your code.