fixed issue 04420: group.php will strip out {QUESTION_ESSENTIALS} if it appears at the very first part of the template in dev branch
Dev used preg_match() instead of strpos() to over come stripping of {QUESTION_ESSENTIALS}
Dev strip out {QUESTION_CLASS} if {QUESTION_ESSENTIALS} is missing.
Dev this issue applies to group.php, question.php and survey.php so all have been updated.

git-svn-id: file:///Users/Shitiz/Downloads/lssvn/source/limesurvey_dev@8911 b72ed6b6-b9f8-46b5-92b4-906544132732