DMV - Brownies Pets (Smart Friendly mobs)

Update v0.5.6:

1. Added the ability to block baby brownies from maturing using a golden dandelion.

2. Added the ability to summon baby brownies by interacting with brownies using a spawn egg.

3. Brownies no longer suffocate in solid blocks (they don't die while sitting on the player's shoulders in low spaces).

4. Optimization