Phone number restriction disabled but checks apply when one is provided
Merge pull request #16 from ningosi/master

Optional phone number
Removed redundant getTags overrides since base implementation returns empty tags array
Fixed WHOStagesAtEnrollments calculation so that WHO STAGE obs will only be considered as the enrollment stage if they're before the program completion date

Also added calculation to the calculation provider
Added WHO STAGE at enrollment to HIV Program summary box, also:
* Renamed MedicalEncounterProgram to ProgramSummary as it is reused across different apps