Give tamed NPCs jobs using tools

Allow a player to use a tool on NPCs to give it a job. Use the NPC formspec to set any needed parameters for the NPC to follow in their job.

### Hoe - Farmer
Clicking an NPC with a hoe gives them the hoe and changes them into a farmer. They will farm within a radius of where they are given a job and will put the farmed items into any nearby chest and replants crops. Better material hoe will improve farming yield and performance. They can be told to follow the owning player to a new farm.

#### actions
- Stand
- Follow
- Farm

### Pick - Miner
Clicking an NPC with a pick gives them the pick and changes them into a miner. They will mine within a radius of where they are given a job and will put the mined items into any nearby chest. Better material pick will improve mining yield and performance and allow the miner to mine harder materials. They can be told to follow the owning player to a new mining area.

#### actions
- Stand
- Follow
- Mine

### Sword - Fighter
Clicking an NPC with a sword gives them the sword and changes them into a fighter. They will fight hostile mobs and players within a radius of where they are and will accept a shield and armor additionally. Better material sword and armor will improve ability and performance of the fighter. They can be told to follow the owning player, stand guard, wander or patrol.

#### actions
- Stand
- Follow
- Wander
- Patrol

### Axe - Lumberjack
Clicking an NPC with a axe gives them the axe and changes them into a lumberjack. They will harvest within a radius of where they are given a job and will put the harvested items into any nearby chest. Better material axe will improve lumber yield and performance. They can be told to follow the owning player to a new harvest area.

#### actions
- Stand
- Follow
- Harvest

### Shovel - Excavator
Clicking an NPC with a shovel gives them the shovel and changes them into a excavator. They will dig holes or flatten areas where they are given a job and will put the excavated materials into any nearby chest. Better material shovel will improve performance. They can be told to follow the owning player to a new area.

#### actions
- Stand
- Follow
- Dig
- Flatten