Final GSoC commit. * Bugfix: Negative frames crashed * Bugfix: JOS sample buffer size prediction error (wasted memory) * Optimisation: for JOS upsampling (around 12 % difference measured here) * Optimisation: Better filter for JOS resampling * Bugfix: Error in relative 3D audio code. * Removed Attenuation * Bugfix: Multiple scenes in BGE lead to errors, BGE audio now all relative, to support multiple scenes.