Added option to display registration agreement as a checkbox instead of an entire page

Signed-off-by: Antony Derham <antonyderham@gmail.com>
Added validation for agreement checkbox

Signed-off-by: Antony Derham <antonyderham@gmail.com>
Added settings check for security and removed line break tags in favour of CSS margins after the agreement box

Signed-off-by: Antony Derham <antonyderham@gmail.com>
Merge pull request #1700 from Ant59/agreement_checkbox

Added option to display registration agreement as a checkbox instead of ...