DOM patching

[tindzk]

Implement DOM patching for better rendering performance. See the following projects for inspiration:

• https://github.com/localvoid/kivi
• https://github.com/livoras/simple-virtual-dom
• https://github.com/infernojs/inferno/blob/master/packages/inferno/src/DOM/patching.ts
• https://github.com/fomkin/korolev/blob/master/vdom/src/test/scala/VDomSpec.scala