add warning to use homebrew for python on OSX in installation notes
Remove Essentia version (outdated 1.2.2) from the text of python tutorials
add python example for beat tracking, rename python examples for consistency
Missing audio files in python tutorials, add instructions how to run tutorials interactively in IPython
forgot to fix audio file in essentia_tutorial_streaming
Essentia python tutorial: output log-scaled mfcc bands in demo
fix a bug thay would compute harmonic weights incorrectly for non-default parameter values
Add info about github branches and descriptor compatibility between them to README.md
Merge branch '2.0'