v0.8.2

Rework tool pathing

• always execute the tool from current directory and stay in it
  (this way relative paths to local in/out-files stay the same)
• pass class path and output directory as parameters to java and javac instead
• add sample and update unittests
• store compiled classes in separate "classes" subdirectory
• common Builder classes to create java and javac commands
• (temporarily) remove parameter out-dir

Misc improvements

• add Github Action to automatically build artifacts and draft a release
• central project (+submodules) version definition
• configure report sources tab-size as 2 in <pre> over CSS (defaut was 8)