Megapatch that fixes/adds: friend offer/deny/accept, friendship termination,

on-/offline updates, calling cards for friends.
This adds methods in the DB layer and changes the MessagingServer, so a full
update (incl. UGAIM) is necessary to get it working. Older regions shouldn't
break, nor should older UGAIM break newer regions, but friends/presence will
only work with all concerned parts (UGAIM, source region and destination
region) at this revision (or later).
I added the DB code for MSSQL, too, but couldn't test that.
BEWARE: May contain bugs.

OpenSim/Framework/IUserData.cs

@@ -135,6 +135,17 @@ namespace OpenSim.Framework
         /// <param name="friendlistowner">The agent that we're retreiving the friends Data.</param>
         List<FriendListItem> GetUserFriendList(UUID friendlistowner);
 
+        /// <summary>
+        /// Returns a list of <see cref="FriendRegionInfo/>s for the specified UUIDs.
+        /// </summary>
+        /// <param name="uuids">
+        /// A <see cref="List"/> of <see cref="UUID/>s to fetch info for
+        /// </param>
+        /// <returns>
+        /// A <see cref="Dictionary"/>, mapping the <see cref="UUID"/>s to <see cref="FriendRegionInfo"/>s.
+        /// </returns>
+        Dictionary<UUID, FriendRegionInfo> GetFriendRegionInfos(List<UUID> uuids);
+
         /// <summary>
         /// Attempts to move currency units between accounts (NOT RELIABLE / TRUSTWORTHY. DONT TRY RUN YOUR OWN CURRENCY EXCHANGE WITH REAL VALUES)
         /// </summary>