Remove NetBeans project files in favor of gradle files + updated docker

[kolakcc]

• Removed included .jar files in favor of dependency managed libaries from Maven.
• Remove dependency on NetBeans, allowing developers to work with any IDE with gradle support.
• Remove other methods of building, delegating all builds to gradle using gradlew build.
• Remove other methods of launching, delegating non-docker runs to gradlew run.
• Update Docker support to add a docker-compose, which will boot a mysql server as well as the server.
• Fix Docker image to remove all unnecessary cruft, lowering build times.

[xinyifly]

This will break the build from a clean clone: build/libs/HeavenMS.jar: no such file or directory

(Maybe you forgot to include ./gradlew build in a multi-stage build?)

[kolakcc]

./gradlew build shouldn't be included in the image, as it will increase the image size and never cause containers to cache due to non-deterministic gradle builds and cache files. The project should be built out of docker for this reason.

[kolakcc]

I've clarified the instructions, using a29c3bc as a base.

• Adjust launch.bat to use Gradle. Can you try it out and see if it works? I don't use Windows.
• Moved instructions about NetBeans to its own section: non-developers on windows ONLY need to hit launch.bat and do not need to fuss with NetBeans and such.