Download all versions of jlayer JAR files with all dependencies

Jlayer version used in libgdx. Fixed some NPEs, changed how buffering happens, deleted most of the classes, everything not related to decoding and half of what was related to decoding but not needed. Added support for reading replay gain out of the mp3.

Jlayer version used in libgdx. Fixed some NPEs, changed how buffering happens, deleted most of the classes, everything not related to decoding and half of what was related to decoding but not needed. Added support for reading replay gain out of the mp3.