COFC variable bounds handling and more complete zoomtilt support

When Zoom out to center is on, the center of the screen is bounded by a "pyramid" with its apex at map center and maximum y distance, and it's base set up so that as long as the camera is below the initial maxDistY buffer, the whole map can be scrolled to. This affects everything except unit and player cursor following, as applying variable bounds there would ruin the intended functionality.

Tilted zoom is also handled by SetCameraTarget if the option is enabled

The start game camera position is also modified to put the camera near the player's commander, not just center on the commander.