Add Java CI workflow with Gradle setup

keeping old ant build file by no reason ..

updating ..

updating ..

adding small gradle manual ..

removing useless local gradle files ..

Update README.md

cleaned code and comments ..

updating JWAVE version ..

updating and refactoring ..

changed to having the Daubechies 20 and the FWT running if no args ..

updating imports ..

updating ..

switching to gradle ..

getting ready for restructuring ..