[Build] add window toolchain hash
[Notification][Linux] Add libnotify to the build package.
[WIN] Make StatusTray class a singleton, add a public function to get the StatusIcon, this is done to fix crash in notification manager trying to create StatusTray that already created by javascript api.
Change DisplayBalloon return param to bool.
Implement more BalloonEvent dispatcher for windows (Show, Hide, TimeOut).
[FlashFrame] abstract class compile error fix (+1 squashed commits)

Squashed commits:

[00816e5] [Flash Frame] change the param from bool to int, [WIN] implementation
[ScreenGeometry] bug fix!! (+1 squashed commits)

Squashed commits:

[aba14e0] [Screen Geometry][WIN] implement display observer for WIN platform
[MAC] Implement DisplayObserver for DisplayBoundChanged, DisplayRemoved, DisplayAdded