Mining, woodcutting, and mob random walking.

- Mining finished

Rune essence mining now is working, along with prospecting.

- Woodcutting finished

Supports multiple players cutting on the same tree, with stumps (not all
correct), being able to get more than one log from every tree except
normal, and tree respawning. This has not been extensively tested so
most likely contains many bugs.

- Mob random walking

Mobs can now be flagged to walk around randomly in the world_mobs.json
file or during runtime of the server with setRandomWalking(value).