Introducing more Keras related functionality

• Introduced recognizer classes: SceneRecognizer, EventRecognizer
• Introduced Keras callbacks: ProgressLoggerCallback, ProgressPlotterCallback, StopperCallback, StasherCallback
• Added new learner classes: SceneClassifierKerasSequential, EventDetectorKerasSequential
  • Full support for Keras sequential API
  • Epoch-by-epoch processing, with external metric evaluation (using sed_eval)
  • DataProcessor class to embed feature processing and data processing chains
  • Feature generators to allow loading feature data from disk during training procedure
• Added possibility to use constant and simple math equations in the keras based learner parameters

Minor updates

• feature_stacker parameter hash added to the data paths. This breaks backward compatibility, previously stored models and results has to be re-calculated or moved to correct paths.

Reproducibility update

• Added Docker container to reproduce baseline results
• Fixed training data ordering (might have been different on different computer setups)
• Added Windows compatibility

First release

• DCASE2017 Challenge baseline system for Tasks 1, 2, and 3
• Development dataset downloading for DCASE2017 Challenge Tasks 1, 2, and 3