Windows: Custom Window Frame does not conform to all standard window behaviors

[FiXato]

When using the default window frame on Windows, a click on the taskbar item for an app will minimise it, basically allowing you to quickly check an app for updates, and then hiding it away if you see no changes.
When you use the custom window frame option of Lagrange though, this will just fade the title bar, and Lagrange will stay visible, rather than be minimised.

[skyjake]

I had difficulties implementing all the standard window behaviors with the custom frame. This was one of the issues.

Another issue was right-clicking the title bar, which should show the "system" menu.

[FiXato]

It's not an important issue, just figured I'd mention it in case it was an easy fix. :)