Rework section title css classes

[sglaser]

Wrap section title in <span class="sect-title">. Add <span class="secthdr" hidden>Chapter|Section|Appendix</span>

The hidden span allows code that references a section to be formatted "Chapter 8" if so desired. This puts the code that picks the name Chapter|Section}|Appendix in one place.

Wrapping the title in sect-title simplifies potential css formatting of the title.

[sglaser]

I'm working on updating the test so this passes.

[marcoscaceres]

ok, cool - appreciate you taking the time to send these fixes. Will wait for update on the tests. Any issues, just give us a shout.