Thank you kindly, MCortez, for a patch that:

This hooks up the LandManagementModule to handle the DeedParcelToGroup 
packet. Now people can start testing land assigned to and owned by groups.
Also fixes a viewer crash issue when searching for and then joining a group 
with an agent that is not already being tracked by groups server.

OpenSim/Region/Framework/Interfaces/ILandObject.cs

@@ -76,6 +76,8 @@ namespace OpenSim.Region.Framework.Interfaces
         void removePrimFromCount(SceneObjectGroup obj);
         void updateLandSold(UUID avatarID, UUID groupID, bool groupOwned, uint AuctionID, int claimprice, int area);
 
+        void deedToGroup(UUID groupID);
+
         void setParcelObjectMaxOverride(overrideParcelMaxPrimCountDelegate overrideDel);
         void setSimulatorObjectMaxOverride(overrideSimulatorMaxPrimCountDelegate overrideDel);