Add some details about recent efforts in Play to support a Gradle plugin and how an incoming Play request triggers a Gradle build. Split Milestone 1 into two milestones - the first being the minimum required to get folks with basic project setups using and testing gradle's play support and the second being what should be worked on right after that
Merge pull request #260 from benmccann/play-design-doc

Add technical details to the Play design doc