* Move initial batch of shaders and presets to smoothing subdirectory
* Rename smoothing to edge enhancement
* Move cubic and windowed into interpolation
* Fix some presets
* Fix rest of presets
* Rename edge-enhancement to edge-smoothing
* Move pixel art scalers into separate directory separate from 'interpolation'
* Flatten interpolation/cubic into interpolation/
- New color distance function to improve IQ;
- Merge noblend and aa shaders in same files;
- Better param descriptions;
- New param to switch between noblend and aa;
- New lv1, lv2-multipass and lv3-9x.