More client security

[est31]

Currently, clients can freely move items around, set blocks, etc. It would be great if clients did local prediction but the server would keep its own log of things to make sure that hacked clients can't do everything they want.

• [x] Only allow placing blocks that are in the inventory: 0b2b981525e62c4b4213e302b65006584e1a511c
• [x] Do inventory movement on the server
  • [x] for chests: 08d3c4846cb5b65bcb14955409c18d09a2235137...45d6561fb7419e1cc76481bcb76b7ad47f4764bd
  • [x] for player inventories: d6f031994ae0139ebeb6482c339665044a4e5e44...dd5e88d3acc0aa4f220fd4f9e07511ee7d22592e
• [x] Do crafting on the server: 83acf29f5a0f01b0821d4cc9084bc6538c0e308f
• [ ] Velocity checking
• [ ] Location checking, verifying that the player isn't inside walls or something