Support for the Broadway backend

[mardukbp]

I just learned that Gtk has an HTML5 backend called Broadway allowing it to render an application in a web browser. This has been demoed with GIMP and LibreOffice.

Then I thought, if we could have hoodle running on a web browser, we would essentially get a collaborative Internet-enabled whiteboard!

[mardukbp]

I just installed hoodle on Ubuntu 16.04 using stack.

Then I ran hoodle with

broadwayd -p 8080 :2 &
GDK_BACKEND=broadway BROADWAY_DISPLAY=:2 hoodle

and localhost:8080 showed hoodle's window. The problem is that the pen does not paint!

[wavewave]

Interesting! I haven't experimented broadway before. Thanks for the try.