Bitcrush: small improvement, also add some stuff to math & constants
Constants:
- calculate all in long double so as to improve the accuracy of our pre-calculated constants
- add some possibly useful constants: reciprocal of pi, square of pi, and reciprocal of e
Math:
- new math convenience functions: absMax, absMin
Merge pull request #1439 from diizy/master

Bitcrush: small improvement, also add some stuff to math & constants