[Bug] Grabmouse and moving the xcom game window

[radish]

I would like to report a bug that should consistently happen across all 1.0 openxcom releases.

Turning on grabmouse as we all know locks the mouse into the openxcom environment which is useful for the battlescape imo.

However if you alt tab out of the xcom window in order to move it the windows environment causes a bug with grabmouse.  Because the game is attempting to lock your mouse into the screen while you are in the middle of moving a window the game causes windows to instantly shoot the game window all the way to the bottom of the screen and there is no way to move it back up again.

Luckily closing the game and reopening it causes it to reopen at its default position in your screen.

It should be a simple fix to program the game to only initialize the window lock after you release the mouse button allowing us to move the xcom window while grabmouse is on.

[yrizoud]

Other workarounds to not lose a game in progress when it happens:
- If a bit of the window edge is still visible, Ctrl-G to disable Grab mouse, then you can drag the window back up
- Alt-enter to enter fullscreen mode