Replace simplemodal javascript library and use Bootstrap's modal

Reference application relies on jquery.simplemodal.1.4.4.min.js library to display popups dialogs in many pages within the application. 

Specifically there is a function in the UI Commons emr.js library that uses this modal library to set up a confirmation modal:

https://github.com/openmrs/openmrs-module-uicommons/blob/master/omod/src/main/webapp/resources/scripts/emr.js#L297

This is an outdated and no longer supported library.   Also, bootstrap.js provides it's own modal function that clashes with this old library (see RA-1673).

We should start using the bootstrap modal instead of the old simplemodal.  To do this, we should:

• Rewrite the setupConfirmationDialog in emr.js so that it creates a modal using the bootstrap modal, not the simplemodal
• Remove simplemodal from the standardEmrIncludes file in appui
• Confirm that the simplemodal isn't used elsewhere within the app
• Post on Talk that this confirmation has been removed so that any distro using the modal are alerted