Create basic encounter form with validation for prior/past date

Create an encounter form that allows users to input a prior/past date only. The suggested concept to use is TB drug start date - ID 1113 available on demo1 instance.

See the following resources for more information:

https://wiki.muzima.org/display/muzima/Reusable+Javascript+Functions

https://wiki.muzima.org/display/muzima/Encounter+Form

https://wiki.muzima.org/display/muzima/Form+Observation+Section

https://github.com/muzima/muzima-android/blob/master/app/src/main/assets/www/forms/js/muzima.js

Sample forms

https://github.com/muzima/muzima-form