Creating of a method that returns the latest date when given 2 dates and
it equivalent unit test, include the cd% parameter into determining
patients who needs the cd4 test based on cd4 counts,cd4% and the latest
date of the two and its equivalent unit test, tb screening form proper
mapping of concept from 1663 to 160737 for the option of not done.
Merge remote-tracking branch 'upstream/master'
Merge pull request #38 from ningosi/master

CD4% included in the determination for due for CD4