The play run and start commands now respect javaOptions

Modified the `run` and `start` commands to respect `javaOptions`. This makes them consistent with the `test` task, so now using `javaOptions` or `javaOptions in <scope>`, you have a consistent way to set system properties (such as `-Dconfig.file`) for all modes. This fixes the concerns in issue #1776.

I tested this manually with an app and it works. However, I'm not sure how to write an automated test, since Play's `test` mode doesn't actually use `run` or `start`; suggestions welcome.