+ update some phpdoc
+ provide support for softDelete methods on elements for custom behaviour when events deleted
+ [OE-2679] allow setting of no known allergy on a patient
+ rename hasAllergy to hasDrugAllergy
+ tweaks to allergy functions
+ display alerts for allergies in patient summary box, and at top of patient summary page.
Merge branch 'master' into demo/orbis

Conflicts:
	css/style.css
	protected/models/BaseEventTypeElement.php
	protected/models/Event.php