Add OG_ROADRGH.dat object (#45)

* Add OG_ROADRGH.dat object

Replacement object for ROADRGH.dat (Road / Rough Road)

* Change tunnel to OG

Change to use OG_TUNNEL2.dat instead of vanilla one

* Set required bridges to OG bridges

Now that OG_BRDGWOOD and OG_BRDGBRCK are created, update the bridges required by the road to use the OG variants instead of the vanilla bridges

Author: shusaura85