SOS Chest Loot

Added artifacts to the sos/message in a bottle chest loot to match OSI-style loot. Also added entry in Fishing.cs to give a 2% chance for a random artifact to drop in the chest when it is fished up. Confirmation links: http://www.uoguide.com/Message_In_A_Bottle http://www.uoguide.com/Publish_68.3 Loot drops are not available other than to say the artifacts are "rare drops".