[ENH] surveys: New type of "question" that's not a question, but a heading to go between question. Will evolve to do more stuff... currently just makes an H3 heading.

git-svn-id: file:///var/local/code.tiki.org/tikisvn/trunk@50512 b456876b-0849-0410-b77d-98878d47e9d5
[MOD] surveys: Remove unused list_all_questions function

git-svn-id: file:///var/local/code.tiki.org/tikisvn/trunk@50513 b456876b-0849-0410-b77d-98878d47e9d5
[FIX] surveys: Don't record that a survey has been taken if there are errors

git-svn-id: file:///var/local/code.tiki.org/tikisvn/trunk@50514 b456876b-0849-0410-b77d-98878d47e9d5