Add python example for MusicExtractor
Add python example for MusicExtractor

- Analyzes audio files found (recursively) in a given folder
- Flags for descriptors to include/ignore
- Wildcards for filenames

carthach/essentia,carthach/essentia,MTG/essentia,MTG/essentia,carthach/essentia,MTG/essentia,carthach/essentia,carthach/essentia,MTG/essentia,MTG/essentia