Addition of new structs and helper functions for passing around pcm clips/buffers and their formats so that we don't have to import and rely on yobert/alsa code.
Updated any commands and alsa package to use refactored code.
added license to lex.go
changed pcm functions to return alsa.Buffers
style, syntax and clarification added to audio.go
new method of finding buffersize in audio.go uses a new function called nearestPowerOfTwo