file gathering, analysis by echnonest, and output

adds gathering of files and processing them with echonest to get tempo,
keysig
uses a conceptual shim to filter down the results to the format already
used and tested
logging, some end-to-end goodness, updated docs

description of what needs to be done.
transitioning to Logbook from Logging and print statements
seems to have everything working end-to-end
more goodness. yeah thats not descriptive.