Update README.md

Update pom.xml

Update score calculate method

improve code quality

This is the *FIRST STABLE* release of MIDI-MUG!

- 3 Game mode! **Real**, **Flow** and **Show** !
- MIDI keyboard support in first release!
- More than **150** instruments!
- Multiple platforms support! **Windows**, **Linux** and **Mac**!

- Mac release might unable to use, since we are lake of mac developers.