Refactored math methods out of SkweekParser and into SkweekMath.
Removed unneeded println statements.
Revert "Refactored math methods out of SkweekParser and into SkweekMath."

This reverts commit b98534208071829e1940f87ae217759cc7a6a0de.
Contains all math methods originally found in SkweekParser.
Moved all math methods to SkweekMath. This is also a simplified version
of the first commit: some methods not used in this application have been
removed.