+ fix optional exceptional circumstances for editing
+ [OEM-177] make change for optional element work with 1.6
+ update RELEASE file
+ [OEM-177] fix for elements not saved in an application for editing
+ [OEM-177] further fix for missing elements when saving partially complete form
+ updated RELEASE file
Merge branch 'master' into develop

Conflicts:
	RELEASE
	controllers/DefaultController.php
+ fix Decision Tree rule admin, tidy up node display (a small amount)
Fix short tags
[OE-4288] - applied fixes to Visual acuity values in template to avoid preview printing problems
[OE-4291] - handle exception and show flash message on event page
[OE-4186] - showing warning and disable submit button/link when email recipient is not configured
[OE-4288] - give a chance to rendering process to finish the PDF
Merge branch 'release/1.7' into release/orbis-r2