Checks whether there actually is an opening <todo tag before inserting a change.
This prevents edit of parent page without todo tag when it includes a page with todos.
If there were todos in parent as well as included page, it would perhaps still break something or do nothing depending on whether the include appears before or after the todo tag in parent page, because we can only count the rendered todos in javascript, not in wiki source.
Checks whether there actually is an opening
<todotag before inserting a change.This prevents edit of parent page without todo tag when it includes a page with todos. If there were todos in parent as well as included page, it would perhaps still break something or do nothing depending on whether the include appears before or after the todo tag in parent page, because we can only count the rendered todos in javascript, not in wiki source.