Checkpoint - assorted updates
- Tested initial jar building (works for engine, modules)
- Updated the module gradle file with remaining content & updates from multiplayer branch
- Tweaked creation & validation of the module.txt, moving it to the setup step rather than every execution
- New createModule[id] task to do that last thing I said, but need to update the Gradle-Git plugin to get an "init" task ...
- Sidenote: Failed completely at getting the new module.txt creation working as in multiplayer branch - Gradle insisted the task was up-to-date no matter what I tried. So rearchitected instead (to a Groovy non-task approach with a more boring ID placeholder), which hopefully will be an improvement anyway (shouldn't really worry about module.txt at build time, more of a setup item) ...