remove all or die
Revert "remove all or die"

This reverts commit 03b0201d1ff9314493645589ae91d86f921c49e9.
properly reverse or die
more exceptions. fix error when item value was not set. also impose limits on study settings params
rollback posting if an error occurs, update existing survey items instead of deleting
unset at end of loop"
unset only after inserts
remove shitty debug
use 'order' field for ordering for survey items
Merge branch 'hotfix/item_display' into develop

Conflicts:
	.gitignore
	Library/Functions.php
	Model/RunUnit.php
	Model/Survey.php
	Model/User.php
	define_root.php
	webroot/admin/run/cron_log.php
	webroot/api/create_session.php
	webroot/superadmin/cron_log.php
	webroot/superadmin/user_management.php