Merge tag '0.2' into develop

Centroid training starting to work
Minor edits
Minor changes, cleanup and notes
Getting reconstruction to work - WIP
Sketched code for reconstruction error - WIP
Another BMP saver - needs refactoring
Better learning rate management
Testing white centroids - they match all on dot product
Updated VQ code (and more tested)
Updated notes
Code reorganization and some bugfix
Shifted dot product is sensitive to both light and darkness

Still not enough, need to implement histogram-based methods at least.
Merge branch 'feature/reconstruction_error' into develop
Merge branch 'release/0.3'