Initial 1.16 update ...

oh lord okay
- Update to new launchermeta endpoint for version manifests
- Fix library handling (libraries now seem to give us the URL most of the time)
- Write entire new system for handling the forge installer process
- Fix asset handling, mostly (still TODO is remove all traces of assetSource, it's given to us by launchermeta now)

Update to Java 9/10. Fancy version is still broken.

[Creator] Don't re-download mods using a download URL every time.

Fix URL override still resulting in a (broken) file copy.

Add new creator tools.

Expand the build tools to encompass many more tasks.

Correct location/to mix-up ...

If .url.txt is used, the manifest file should specify that as the download location, not the local "to" location

Switch to Gradle. Use git log --follow for history. ...

This converts the project into a multi-module Gradle build.

By default, Git does not show history past a rename, so use git log
--follow to see further history.