tpga version 17c

I actually forgot to update the changelog in the game files, so here's what's changed.

v17

• Added terrain settings.
• Added caves.
• Added badlands.
• Added clay, mudrock, and sandstone in the badlands.
• Added ores of calcite, gypsum, salt, epsomite, borax, natron, and nitre.
• Added limestone and dolomite.
• World generation seeds can now be entered.
• Certain biomes might have had trees when they shouldn't.
• World seeds can now be as high as 16777215.
• Decreased maximum world height to y=253.
• Fixed a bug causing the stone types to repeat every 64 tiles instead of being continuous.