Merge pull request #1 from GlitchCog/master

Updating My Repo
- Fixed Chebyshev Heuristic calculation and modified the explanation to
more closely match the classical definition.
- Added Diagonal Heuristic to perfectly match 8-directional movement.
Added to GUI.
Updated README
Fixed spaces
Merge pull request #3 from ClickerMonkey/master

Fixed Chebyshev calculation and added Diagonal heuristic