* Get rid of isSelected, canvas, canvasZoom, canvasOffsetX and canvasOffsetY on ExcalidrawElement.
* Fix most unit tests. Fix cmd a. Fix alt drag
* Focus on paste
* shift select should include previously selected items
* Fix last test
* Move this.shape out of ExcalidrawElement and into a WeakMap
* Disable text selection
* Set content-editable=plaintext-only to disable Touch Bar formatting buttons
* Enlarge resize handle tap targets for pen/touch
* Make the lock button a button in mobile mode
* Use icons instead of Unicode characters; add an alternate toolbar for creating multipoint lines
* Allow buttons to hide themselves
* Fix heuristic for showing shape actions
* Refactor icons
* Fix label for edit button
* Switch edit button icon
* Remove lock button on mobile
* Add language selector on mobile
* Fix showing edit button on mobile
* Fix showing edit button on mobile, part 2
* Fix handle touch regions
* Fix scroll-back button position
* Allow using the text tool on a text object to start editing it
* Fix deletion of last point in line
