Added a function to do bulk creation of output variables.
Merge branch 'master' into simpler-reporting
Merge branch 'master' into simpler-reporting
None of the modules use RPT_group output variables anymore. Instead, the modules store 1D or 2D arrays of output variables when they want sub-categories or sub-sub-categories.
Removed the "1 level deep" versions of several functions for output variables.
Deleted the RPT_group output variable type and all code that used it.
is_null is now just a field lookup, not a function call.
Added variables for adequate exposures broken down by cause.
Removed some useless output variables that get created just because of the loops over all possible contact types, control reasons, etc.
Merge branch 'master' into simpler-reporting

Conflicts:
	CEngine/modules/full_table_writer.c
Restored some changes accidentally overwritten in last merge.
Removed the subelement argument that several of the output variable functions used to take.
Merge branch 'master' into simpler-reporting
Fixed a few loops to get rid of “‘for’ loop initial declarations are only allowed in C99 mode” compiler warnings.
Put back the unitDaysInZoneBackground and animalDaysInZoneBackground outputs. Removing them should be an analyst discussion.