Lagom build system features should be consolidated into the Play build system

[gmethvin]

The ability to run multiple services in dev mode and having infrastructure services should exist in Play. There would probably be a different process for sbt and for Maven, since Play's support for Maven is third-party. It would also be nice to add these features to the Play Gradle plugin since customers have asked about Lagom support for Gradle.

This effectively makes the difference between "Play" and "Lagom" one of which modules are used.

[TimMoore]

In Stockholm this did not make the cut for priorities this quarter, so I'm moving it back into the backlog.

[ignasi35]

Some improvements are already pushed into Play (from Lagom) in playframework/playframework#7294.

[TimMoore]

Closing in favor of moving to the @lightbend/play-lagom team road map.

[mkurz]

Still relevant...?

[ihostage]

I think that no. We have #8 as EPIC for this.