fix videopaint feedback loop

[Jheronymus]

In the drawing screen the page also lissens to it's own drawing messages. So they are doubled.
Perhaps add an origin to the message?

[rikkertkoppes]

Don't draw on mousemove, only send messages. Then draw on message received.

Then check for responsiveness. If it lags too much, it is not a workable solution. But this is the approach in other modules

[Jheronymus]

add an option so you can toggle between local and network use.

[Jheronymus]

please look at the example in the control panel module how the system checks if it is used locally or via mserver

[Jheronymus]

got things mixed up. Sending and listening to non local events adds to much delay.