snarltraynotifications: code to bypass the default balloon

Did a few updates to Snarl Tray Notifications (see the project page) - the app now hides the original message; only the Snarl notification is visible. It's usable now, except for messages requiring interaction with the mouse.

You may also notice, it has an icon now. Thanks to Sekkyumu at deviantart. The icon display code is temporary, as I plan on grabbing the original icon from the original message, so we'll see what happens.

Until the next update!