Changes from v1.0.0:
- sync with shapes editor library v0.8.0
- fixes various bugs related to reference boxes and percentage-based coordinates;
- adds on-screen controls for polygon edit / transform modes;
- uses minified version of library;
- removes keyboard shortcut (T key) to toggle polygon transform mode.
- removes handling & feature detection of
shape-inside(obsolete from CSS Shapes Level 1)