Fix sending Armor & Held item

Fixes Armor being sent to the incorrect slots on the client.
Enables held item slot being sent to the client properly, also sends it when the entity spawns.
refactored PlayerArmorInventory to EntityArmorInventory as other Entities will be getting this.

Signed-off-by: Nick Minkler <sleaker@gmail.com>
Merge pull request #539 from Sleaker/master

Fix how we handle held items, and armor slot changes to other clients.