HP bar, more blocks/recipes/NPCs, better pathfinding

- added gates (only open for friendlies)
- added flower patches
- added a garden tile crafting recipe
- made AI players use the pathfinding system to build
- if there is a block on the target tile, set target to first open adjacent tile
- pathfinding now checks for entities (but ignores Gates that share a mutual owner)
- balanced tool strengths a bit
- added right click menu for owned NPCs
- added Archers
- added Builders (they repair broken blocks, soon tiles)
- working on getting all NPCs to do things depending on their current mode
- gave human players 1000 food points (testing purposes, not permanent)
- some entity spawners will change their output based on surroundings
- destroying a garden tile will reduce the owner's food points