Syphon paint (source) on macOS

[aalex]

Add Syphon support on macOS through a special Paint.

[sofian]

Splash contains code for interop with Syphon, looks pretty neat. https://github.com/paperManu/splash https://github.com/paperManu/splash/blob/master/src/texture_syphon.cpp

[sofian]

Also: https://github.com/paperManu/splash/blob/master/src/texture_syphon_client.mm

[aalex]

http://stackoverflow.com/questions/2355056/how-to-mix-qt-c-and-obj-c-cocoa

[aalex]

Here is how to compile a Qt project against the Syphon framework: https://github.com/Delicode/Vidiot/blob/master/Vidiot.pro#L147

[sofian]

@ltsadair has started working on this issue!