prepare docs for 2.3.4

Migrate jsbins to github gists #673

Conflicts:
	documentation/img/demos/aqupun.png
	documentation/img/demos/domek.png
	documentation/img/demos/kewem.png
	documentation/img/demos/wuvac.png
	documentation/img/demos/yeqom.png
String stylesheets don't recognise `core` #694
 Disable wheel-to-zoom within threshold of page scroll #695