Add new data center IT equipment model

First draft of source code to add ElectricEquipment:ITE:AirCooled object to model data center IT equipment.
@kbenne Please review this change here and in line 1542.  When I changed the new ITE example file 1ZoneDataCenterCRAC_wPumpedDXCoolingCoil.idf (in this branch) to run with design days only, I tripped an array bounds error on this line of code.  Appears that lastDayOfMonth is dimensioned [0,11] and month is from [1,12]?