Allow notable inventories in events (and that's not the best part!)

This pull request:
  - uses auto-generated colors to track notable inventories (Fixes #707)
    - note: for notable inventories, titles must be 26 characters or less. any excess will be cut off.
  - fixes offline player data
  - reworks enderchests (thanks @mcmonkey for some code)
  - allows <p@player.enderchest> to work offline
  - adds implementation for all generic inventories to have titles
  - uses UUIDs in all (?) inventory identifications