Option to Suppress Tray Messages

[tresf]

On Windows, you can suppress tray messages, but only if the icon is hidden.

We like these messages for the demo page (and for all dev/testing) but they are way too verbose for production use. We need a way of disabling them for a particular connection.

Mac does not appear to have such an option.

The software should have an option to suppress the popup messages.

[Vzor-]

I'm starting this one on my fork.

[tresf]

Closed via 8e10923

This feature will be available in 1.9.5, expected on or around December 23, 2015.