Prehistoric stuff

Visit the great puffersaur with this update, apart from the previous content, enjoy:

• The beach mangrove biome
• New mangrove grasses both normal and sandy
• The ancestral burrow, the new structure
• The puffersaur egg, which when placed will make this new mob appear
• When you right click on the puffersaur with scissors it will give you its scales
• With the scales of the puffersaur you can make the ancient spear, which will allow you to poison and kill mobs.
• Three new achievements
• Nautilus AI changes