priority groups now defined in Parameters instead of EpidemicDataSet. also using shared_ptr's for priority groups.
added PriorityGroupSelections class and corresponding widget class. added StockpileConsumptionWidget to dock to modify antiviral and vaccine consumption priority groups, which are now included in Parameters.
antivirals and vaccines can be applied to specific PriorityGroupSelections. non-overlapping stratification value sets can be retrieved from PriorityGroupSelections. defined getValue() in terms of stratification value sets.
adjusted formatting in event message for better display through DisplayCluster.
updating title when stockpile map type changes.
changed ":infected" derived variable name to "All infected".
renamed other derived variable names.
changed antiviral / vaccine capacity defaults.
annotations in ParametersWidget.
changed labels for backward, play, forward buttons in GUI.
renamed Stockpile Consumption dock to Policy.
log messages for antiviral and vaccine priority group selections.
simplified antivirals model for a fixed one-day treatable period.
vaccines model shouldn't consider already-canceled schedules (e.g. in a previous treatment).
comments for some TODOs.
removed default priority groups.
Merge remote-tracking branch 'knolla/master' into knolla-merge

Conflicts:
	src/EventGroupThreshold.cpp