adding Entropy algorithm, examples in freesound extractor
Merge pull request #128 from g-roma/master

adding Entropy algorithm, examples in freesound extractor
improved doc
add new spectral_entropy and hpcp_entropy descriptors to music extractor
compute spectral_entropy with equal-loudness filter
AudioLoader bugfix: incorrect output was produced on frame decoding errors. Closes #64
extractor_music:  more verbose output about processing steps
freesound extractor: adding gfcc, hpcp_crest
update doc for HPCP, mention that hpcp vector starts from note A
Merge branch 'master' of https://github.com/MTG/essentia
freesound extractor: adding hpcp peaks count
compute md5 hash over undecoded audio in AudioLoader, new extractor for md5 values

- new output "md5"
- adapt MonoLoader and cpp tests
- new extractor for md5 values
Merge branch 'master' of https://github.com/MTG/essentia
remove build code for outdated extractors from build script
compute md5 values in music extractor
fixed indentation error
Read packets with multiple frames correctly instead of dropping consequent frames. Closes #37
fix unittest for BinaryOperator
fixed incorrect zero division check in BinaryOperator
Output libav error text on av_audio_convert failure