ClickThroughAlpha for windows

[AnrDaemon]

Reported by alurcard2, Jul 29, 2013
There should be a setting to allow you to click through pixels where the alpha value is < some threshold.

[AnrDaemon]

Note in implementation: This should be optional for any child windows created from the module. Else f.e. tray icons with alpha channel will be hard to hit.