* extract_pose_from_pose only checked one of the list items for NULL when looping over them yet its possible they are different sizes.
* game_free_pose needed to be used rather then MEM_freeN, channels would never be freed leaking memory.
* setChannel() would make a new pose that wasnt aligned with the existing pose, the lists are assumed aligned so when extracting the channels its unlikely this was ever useful.
* Added getChannel() - returns pose loc/size/quat
* Added option args for setChannel(channel, matrix) or setChannel(channel, loc, size, quat)