Revscoring

Fixed
- Fix bug where `max()` arg is an empty sequence.

Added
- Added minimal implementation of Turkish language

Changed
- Improved behavior of MLScorer and MLScorer model.
- Improved README.

This is an early release of the revscoring library.

Added
- Added revscoring.datasources (Datasource, 20 implemented)
- Added revscoring.extractors (APIExtractor)
- Added revscoring.features (Feature, 42 implemented)
- Added revscoring.languages (english & portuguese)
- Added revscoring.scorers (MLScorer/MLScorerModel, SVCModel, LinearSVCModel & RBFSVCModel)
- Added revscoring.dependent (Dependent, Solve)
- Tests for all new modules.

Added
- Explanation of the recommended reverse chronological release ordering.

Added
- Basic project setup.