The URL is interpreted relative the current page, not relative
the current script. So we need to have some extra code in order to
allow the module loader to be agnostic to its path.
This commit makes vnc_playback.html functional once more, and completely
refactors tests/playback.js to make it usable in other scenarios.
In order for vnc_playback.js to properly load playback files now, they
must `export` their variables.
This commit moves the global error handler into a separate file,
so that it can catch module loading errors.
This also adds support for properly displaying error messages with
newlines in them (since the module loader may throw those)
This commit makes the ES6 module loader polyfill use Web Workers,
so that Babel doesn't block the browser from animating. It also
uses localStorage to cache the compiled results, only recompiling
on source changes, so it makes loading faster while developing noVNC.
This includes a vendored copy of the ES6 module loader, modified as
described above.
