Fixed CalculationResult Bug in WhoStageAtArtStartCalculation + Fixed Concepts

Fixed bug in WhoStageAtArtStartCalculation causing CalculationResult to be given a value for the WHO Stage obs even when NULL/UNKNOWN is saved in the database. See PT story: https://www.pivotaltracker.com/story/show/62142144

Added unit test for Fixed bug in WhoStageAtArtStartCalculation.

Removed hard coded concept id for STAVUDINIE and added the UUID to the Dictionary class.

Added missing concept on delivery form (resuscitation)

Changed partner HIV test date concept on MCHMS enrollment from 160082 to 162079.