Use a byte buffer for audio to minimize buffer copy's

I have replace the usage of byte[] in short[] for audio. This helps me to remove a extra buffer which is used in audio decoding (which is really slow on the Raspberry Pi). The changes needed in Java (for Limelight-pc) are available on irtimmer@27366b14fc24a8a95589b87dede5b03b6dbeace3 This last commit also contains some change in the C code that are not correct. These are corrected in irtimmer@6626195176d7d6baee1c3a720fc8d14bbe5c54e3

For android I currently have no code changes available, but I guess it's not that difficult to port the code.