* include promise polyfill

* remove es6

* add viewBox to every icon

* change self closing to explicitly closing tags

* replace window.scroll.. with document.documentElement.scroll..

* verify document.activeElement.blur() is a function before calling

* fix visuals of color chooser (colorpicker still sometimes buggy)

* do not attach to mouseleave event in IE

* attempt removal with usecapture true in IE as well, this fixes the tool switching issue

* fix text tool for IE

* fix cursor for IE

* change curMode to boolean and rename to 'active'

* replace minified canvascolor with unminified code

* replace if else structure with switch statement

* compile polyfill for each browser individually

* remove static polyfills from board.js

* Fix broken js reference

* Fix unused variable and empty console log

* Allow serving non-minified polyfills for easier debugging

* Add proper caching for polyfill.js

This request is on the critical path, we should try to make it fast

* Include more polyfills

All the DOM polyfills were missing

* Update dependencies

* Add missing polyfill

Our custom polyfill was deleted, but the one from polyfill-library hadn't been added

* Remove feature detection for Node.contains

We now have the function in the polyfills

* Update polyfill caching logic

* Remove content-Length header

Co-authored-by: @lovasoa