Fossils and NPCs

• Added a new salty bone blocks set
  • A brighter and whiter version of the vanilla bone blocks
  • Complete with a full block, ribs, long ribs, spine, spike, and long spike
• Fossiles now generate in the salt flats using these new salty bone blocks
  • Most are small, but some are rarely gigantic, spanning dozens of blocks
• Scorpions and desert chickens now spawn inside ravines
• Vultures now spawn anywhere in the salt flats in groups of two
• Geckos now spawn near red sandstone formations
• Fixed salt flats fragment not requiring memories to craft