FireDragon's Custom Models

- Added a single stem option for Pumpkins and Melons, removes the secondary bottom stem
- Added a "Vanilla" name option, this is useful when natural spawns is enabled so you can force a custom textured mob to have the vanilla texture (the name only has to include "Vanilla" it does not have to be exact)
- Added nautilus color variants
- Added a glowing variant of the zombie nautilus
- Added minimal nautilus armor as a renamed item, allows the shell to be more visible and has variants for all the materials in the pack