Add MaterialData for Dirt

This adds the possibility to identify the three types of dirt: normal, coarse and podzol.

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*Edited by turt2live*

**Related links:**
- Glowstone: None needed
Your changes are much better. Thank you! 

And I didn't realize English wasn't your first language, I just thought that these were just mishaps in typing. Great job on the English skills I suppose ;)