[Spice-devel] RFC - SPICE port draft implementation

[Oliver Gutierrez]

This is a fist draft of the SPICE port feature in spice-html5

There is only support for receiving messages right now.

The port-event and port-data callbacks are set just like other javascript event listeners in the window object (Maybe we can move this to the main channel)

Also we need to move code chunks to places its intended to be (remove the examples of event listeners, moving the SPICE_MSG_PORT_INIT message class to the mesages file, etc.)