#155 Knight movement combo box no longer allows exact or inverted (1x2 = 2x1) duplicates.
Merge branch 'master'
#155 Bidirectional movements now stored in a Set, less hacky list manipulation, renaming knight-like variables to bidirectional names
Merge pull request #162 from awolfe9/KnightMovementDuplicates

#155 Knight movement combo box no longer allows exact or inverted (1x2 = 2x1) duplicates.