Browser support/polyfills

[eah13]

Running list:

• [ ] object.Proxy() - no IE support
• [x] object.Assign() - no IE support

[albertjan]

• https://github.com/GoogleChrome/proxy-polyfill
• https://github.com/babel/babel/tree/master/packages/babel-plugin-transform-object-assign

[albertjan]

object.assign is built in by babel. Proxy how ever is proving to be a problem. I will investigate if we can do without it.

[albertjan]

Inform ie11 users, that processing.sk doesn't work.