Release Tests: Validate JarHC with JarHC

[smarkwal]

Analyze JarHC with JarHC and parse the report.

Assertions:

• JAR does not contain Java 9+ classes.
• No unused dependencies.
• No missing classes or other binary compatibility issues.
• No blacklist issues, except System.exit(int) in class Main.
• others?

May depend on #114.