SKQW: download ældre versioner

Features
- Breaking API change: the skqw object is no longer passed to lifecycle methods.
Use require('skqw-core') instead.
See docs for ore information about the new APIs
- Only load scripts on demand, rather than keeping whole library in memory
- Error messages in console when visualizations fail to load
- Abort broken scripts after too many exceptions are thrown
- Automatic updating of parameters when no callback exported
- Bundle skqw-utils module, currently featuring an exponential smoothing implementation and crappy beat detector
- Bundle a set of default visualizations with the app
- Updated UI