webrenderTOP: Add 2 way communication via JS

Please add 2 way communication with webrenderTOP. Just allow the executeJavaScript command to return data instead of None.


While setting the page title to some parsable string is a solution for me personally, this would greatly improve the workflow for doing cool things with webrender top (like UI)


Anyone feeling comftable doing UI in webrender?

That used to be a nice option, but now we have BINDINGS!!