Adds sounds to most vanilla creatures, to be heard in adventure mode. More info in the readme and forum thread.

Changelog -
===
v.02
First update. Incorporates .34.02's raw fixes and adjusts some existing sound frequencies. New files:
creature_next_underground
creature_subterannean

v.01
Initial release. Contains the following finished text files:
creature_birds
creature_domestic
creature_large_mountain
creature_large_ocean
creature_large_riverlake
creature_large_temperate
creature_large_tropical
creature_large_tundra
creature_savage_tropical
creature_standard