[1.0 Bug] Positioning a Plane with the Gizmo

This is an issue with both the ground and water planes. It is very difficult to position the plane by dragging the gizmo, for a couple of reasons. First, the gizmo renders at the origin (0,0,0) no matter where the plane's real position is and does not move with the plane as you drag it. Second, when you grab the gizmo and start to drag the mouse, instead of the mouse movement distance correlating to an absolute world space distance, it looks like with each mouse event the plane position accumulates until it is out of control. For example, you start dragging the plane along the z-axis, and it starts out moving smoothly in small increments, but quickly starts moving in larger and larger increments until it's jumping around wildly.