* Add a task to compare public APIs for every stable module.
* add a few comments and make the build task depend on the japicmp task
* update the api diffs after rebasing.
* task must depend on jar
* a few script tweaks based on feedback
* small tweak to make it a little more kotlin-idiomatic
* refactoring to make the code more clear
* some more refactoring.
* make the latest released version a lazy val of the build script
* have the task depend on check, rather than build
* put all the API diffs into a central directory
* run at --info to diagnose CI issues
* try an older java 11 version
* try another combo
* remove the info logging
John Watson