Add RefrigerationWalkInZoneBoundary and more updates

Adds RefrigerationWalkInZoneBoundary to hold data for
RefrigerationWalkIn extensible group. Add methods to
RefrigerationWalkIn to [add,remove,removeAll]ZoneBoundary.
Add ForwardTranslator...[SecondarySystem,WalkIn]

Adds ForwardTranslatorRefrigerationSecondarySystem and
ForwardTranslatorRefrigerationWalkIn.

Updates ForwardTranslatorRefrigerationSystem.
Update SecondarySystem, add unit test, and more

Adds unit tests for RefrigerationSecondarySystem.

Updates RefrigerationSecondarySystem to add remove(), clone(),
children(), and constructor

Updates RefrigerationSystem cpp and unit tests for new refrigeration
objects.
Update Walkin, WalkinZoneBoundary, and unit tests

Updates RefrigerationCase, RefrigerationWalkIn,
RefrigerationWalkInZoneBoundary for core functionality.

RefrigerationCase removes requirement of caseLightingSchedule in CTOR

Updates unit tests.
Update ScheduleTypeLimits::units()

Adds "watts" and "wattspermeter" to ScheduleTypeLimits::units() for use
with ScheduleTypeRegistry singleton.
Merge branch 'RefrigerationPart2' of https://github.com/ORNL-BTRIC/OpenStudio into RefrigerationPart2

Conflicts:
	openstudiocore/src/energyplus/CMakeLists.txt
	openstudiocore/src/energyplus/ForwardTranslator.cpp
	openstudiocore/src/energyplus/ForwardTranslator.hpp