adding class to perform calculation of the number of days a series of date ranges exists for regardless of overlaps or gaps between ranges.  This will assist in a more robust cumulative medication duration calculation as overlapping medications and gaps can be accuratly computed
implementing CMD based off of ActiveDays class. Handles CMD based on order or fullfilmentHistory
removing debug logging
Merge branch 'cmd_recalculation', fixes #15
Update TIMEDIFF to handle groupings, using first and last events
Utilize events rather than events.eventLists for handling TimeDiff on Unions
Add comment for Union-handling code