Clean chat event handling a bit

Denizen currently handles ASync / Sync chat events really weird... this
is the first step in cleaning it up to be handled appropriately --
moving the world events to Smart events, and making the ugly async code
non-default in the config file.
(Currently our Async code just forces sync, which is fairly pointless
and dangerous)
Add entity health mechanisms

dEntity.health, dEntity.max_health mechs for easy health adjustment
(health/heal commands work too though...)
Also fix some meta typos
Make entity.eid/uuid available even for unspawned, fixes #737

These tags are still valid, even if the entity has not yet been spawned
/ is already dead.
add chunk.cuboid

A quick tag to get a cuboid from a chunk
also fix up cuboid's identify - I'm not sure what was wrong with the
original, but it's output was nonsense (probably weird char handling or
something... either way, excessive .append works!)
Bug fixes and code cleaning

- Random cleaning
- Don't clear the wrong event for sync player chat
Merge pull request #738 from mcmonkey4eva/master

Pull request for entities and such