Some simple arithmetic functions
Moved test files around
Updated core.logic
More tests
Fixing a failing test by upgrading to core.logic 0.8.3  (Thank you David Nolen)

http://stackoverflow.com/questions/15671823/unexpected-results-with-clojure-core-logic-using-clp-fd
https://github.com/clojure/core.logic/commit/52eec3b04c2b785c84bed81671db80c2163c4967
Exploring months and leap years
Fixing tests, cleaning house, and moving files