Change modules's init files
Move aubio analyzers in timeside.analyzer.aubio sub-package
Automatic discovering of processors

- Automatic discovering of processors by walking through timeside decoder, analyzer, encoder and grapher subpackages.
- Empty corresponding __init__ files i.e. remove explicit import of processors
Fix documentation and doctest
Fix doctest
Fix PEP8
Fix importError for Yaafe and Aubio
Fix many PyFlake warnings
Merge branch 'package_structure' into dev