ToolChain

Hi again

I dive in the plugin a bit and compare it to other gradle plugins (spring boot) and other gradle plugins look like it require quite a bit of refactoring:

1. The runPlay should extend from JavaExec - and should take in consideration the ToolChain configuration
2. The forkOption is not properly configurable and each time a RunPlay instance is created it is set to new BaseOptions - instead of using the lazy property configuration
3. Server and Client WorkProcess are not properly configured when created looks like not all running JVM are properly delegated to those process
4. Multiple use of deprecated api
5. More...

I am willing to contribute to this plugin but I will need some mentoring and some references from someone from the Gradle team.

Thanks