added some filters
added tags.txt to package_data
added echonest and idiomag as dataproviders, updated usage and config
version 0.1.19

added echonest and idiomag as dataproviders
added -c/--cacheignore command line argument
added sources and cachetimeout config option
removed --no-<source> command line arguments
removed artist score multiplier (more artist only sources now)
improved config file handling
handle keyboard interrupt
various code improvements