FIX #1617: reloading didn't change the :browse output as it should
The problem was that because the interface hadn't changed, we were re-using the old ModIface. Unfortunately the ModIface contains the GlobalRdrEnv for the module, and that *had* changed. The fix is to put the new GlobalRdrEnv in the ModIface even if the interface has not otherwise changed. ModIface is not really the right place for the GlobalRdrEnv, but neither is ModDetails, so we should think about a better way to do this.