[feature] support overlay for errors and warnings

[gabrielcsapo]

This feature would be similar to https://webpack.js.org/configuration/dev-server/#devserveroverlay and would look like the following.

Instead of having to monitor the console for errors it would be great to throw an overlay up and alert the developer that something has gone wrong. We have all of this information available and it should just require styling it to show up when the developer has configured it.

[rwjblue]

Hmm, sorry but I don't see how this is related to live reload. What am I missing here?

[gabrielcsapo]

@rwjblue When there is a failure in the build, live reload will not load the page. I am suggesting that live reload show the error in the context of the application so that it:

A. Provides a larger canvas to display the stack trace
B. Doesn't require switching contexts if the developer is only looking at their editor and the browser

[gabrielcsapo]

@rwjblue does this seem like the right place for that?