Fix the name of the library in non-module loader browser environments.
Previously, the library was attached as window.none. Now it is available
under window.momentBusiness. Note that this issue does not affect users
building with ES2015/CommonJS/AMD module bundlers.
The functions in this library now accept moments as arguments rather than
being attached to the Moment prototype.
The behavior is weekDays and weekendDays now aligns more closely with
Moment.prototype.diff. If the endMoment passed in comes before
startMoment, then the result will be negative.