New hotkey shortcuts, added NPCs, fixed bugs

- fixed hotbar alignment in InventoryMenu
- added "medic" (doesn't work!)
- fixed phantom torch (I think)
- fixed getTile() returning null
- fixed grass not being replaced with ore on break
- CTRL click an item to add it to hotbar
- gamesave now includes hotbar configuration
- reduced flower count in world generation
- fixed NPCs not dropping items on death
- fixed equipped item texture not resetting when you do not have an item selected
- added methods to get the ID and class of a specified hotbar slot