Added prospecting skill. This skill is increased by using a propick and by successfully finding an item while gold panning.

Prospecting Ranks cause the player to see less false negatives while using the propick. When panning, higher ranks allow for more ores to drop more often.
Gold from panning can now only be found when the players skill is at least Expert. Silver has been reactived and requires Adept rank.
Additionally Propicks have had their base durability cut to 1/3 of its original value.