Section summaries and titles are not greyed-out when sections are hidden. This confuses users, who are not sure whether the text is actually hidden, unless they change role to student to check.

Steps to reproduce
==================
1. In a new course, edit any section summary, giving it a custom title and some summary text.
2. Add a resource to the section.
3. Click the 'hide' button on the right of the section.

Expected behaviour
==================
Everything in the section should go grey to indicate that it is hidden from students.

Actual behaviour
================
The resource goes grey, but the section title and summary do not.