work on timekeeper
create beat loop in timekeeper
comments only
minor comments and spacing changes
little refactoring + adding comment around the creation of a "type-of-primitives" index
Exclusion-principle wobbling: objects wobble a bit if they are painted consecutively in exactly the same place.
timekeeper connects to pulse, supplies beat/pulse/wave
remove empty file
Merge branch 'refactor-events' into refactor-bpm. Including the stats widget fix.
minor code formatting
support for scoped matrix transformations + test cases

e.g.
rotate
▶box
minor formatting and comments
some comments
exclusion principle step must be skipped when both fill and stroke are drawn, otherwise the "stroke" sets a slightly larger place and the "same place" detection fails
now also move and scale support local scoping, just like rotate
adjusted proportiong of all the primitives. Fixes #66
Updated language intro with info on "scoped matrix transformations", plus corrected a minor disfluency.
Update language intro with info/example on the the super-short transformation scoping (primitives inlined with a transformation)
Minor updates to language intro
added a "ribbon" example