Added Fix Pistons Command

### Description ###
Fixes buggy or broken pistons by intelligently scanning them and checking their metadata.
### Usage ###
Make a world edit selection and type /fixpistons. This will scan the error for bad pistons and fix them.
### Overview ###
Fixes 3 different types of know piston issues.
* Piston Extension is there but invisible
* Piston Extension is missing but the piston base acts like it is extended
* Piston Extension exists but the piston base acts like it is retracted (classic derp pistons)

### Notes ###
It will also check for the base thinking it is extended, and the extension being present, but the meta-data being invalid ( Such as the piston extension facing the wrong direction )

Let me know if I should add anything, sorry about the double commits. Nano derped my line endings.

_Regards, NeverCast_