* Serve iframes from another local port when running on http
* Use relative hostname in local iframe URL
* Simplify server start check
* Use random iframe port when Livebook runs on a random port
* Rename space/ to iframe/
* LivebookWeb.IframePlug -> LivebookWeb.IframeEndpoint
* Set up Escript packaging
* Use MD5 digest sa ETAG
* Make sure changes to the static files recompile the relevant module
* Manually start the application in Escript
* Set up basic CLI
* Run formatter
* Start Elixir app before anything else
* Improve version output
* Build Escript to project root directory
* Improve assets handling
* Move plug related modules under plugs directory
* Include bundled assets in the repository
* Use the same plug with different static providers in prod and dev
* Refactor providers
* Rename StaticProvidedPlug to StaticPlug
