Changes

--nil = unknown.

--nil = unknown.

--Otherwise a table with obtainment methods under numeric keys and optional detailed data under the obtainment method key.

--Otherwise a table with obtainment methods under numeric keys and optional detailed data under the obtainment method key.

--E.g. {"buildable", "drop", "event_reward", "event_drop",  

--E.g. {"drop", "event_reward", "event_drop",  

--      drop = {{1/*world*/, 4/*map*/, "B"/*node*/, 3/*formation (optional)*/}, {3, 2, "A"}},

--      drop = {{1/*world*/, 4/*map*/, "B"/*node*/, 3/*formation (optional)*/}, {3, 2, "A"}},

--      event_reward = {{2016/*year*/, 4/*1 = winter, 4 = spring, 7 = summer, 10 = fall*/, 5/*map*/}},

--      event_reward = {{2016/*year*/, 4/*1 = winter, 4 = spring, 7 = summer, 10 = fall*/, 5/*map*/}},