This is definitely going to break the build (it shouldn't, but these
things always do). Anyway...
- Use the new Java toolchain support, rather than requiring the user to
install multiple Java versions.
- Bump versions of several plugins.
We're sadly stuck on Gradle <7 for now, as they drop the old
maven-publish plugin, which drops SCP support.
Updated the source code to the version shipped as the 1.80pr0 alpha
release. Also removed some unnecessary files from the LuaJ subfolder
which were bulking up the repository.
Jonathan Coates