Fix bug in BigRational equality
Fix bug in BigRational equality

Also removed === and =!= in LongRational. LongRational
is a private class, and we only want === and =!= in public
classes.

siddhartha-gadgil/spire,codeaudit/spire,tixxit/spire,JackSullivan/spire,non/spire,kevinmeredith/spire,JackSullivan/spire,adampingel/spire,tixxit/spire,guersam/spire,siddhartha-gadgil/spire,guersam/spire,codeaudit/spire,rklaehn/spire,rklaehn/spire,adampingel/spire,kevinmeredith/spire,non/spire