[done] Option for Camera movement when mouse on window borders

[Omega]

^{As per https://forum.megaglest.org/index.php?topic=7477.0}

When you move the mouse to the borders of the game window, the camera will move in that direction. This is an intended behavior and many players will make use of it. However, some players have voiced that they would prefer to disable this feature (the camera can also be moved with the arrow keys, by default). An option, preferably in the INI and the options menu, that could toggle whether or not this behavior occurs would ensure everyone is happy. The current behavior should remain the default.

[softcoder]

svn now supports this in glestuser.ini (will eventually add to the options menu):

MouseMoveScrollsWorld=false