This is a minimal version of qtloader. The load function accepts
the same arguments as emscripten runtime with a few additions:
- qt.environment
- qt.onExit
- qt.containerElements
- qt.fontDpi
- qt.onLoaded
- qt.entryFunction
State handling has been removed in favor of making the load async
(assume loading when the promise is live).
Public APIs getting crashed status, exit text and code have been
refactored into the new qt.onExit event fed to load. No need for
keeping the state in the loader.
The loader is integration-tested. A test module with test APIs
has been created as a test harness.
The runtime APIs exposed by Qt (font dpi and screen API) are handled
by the qtloader seamlessly.
Change-Id: Iaee65702667da0349a475feae6b83244d966d98d
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>