[TIDOC-931] Return class attribute fragments for section URLs

Testing:
Generate documentation with -s option.

Try out these URLs:

These should return only the attribute snippets:
[URL]/?_escaped_fragment_=/api/Titanium.UI.Label-event-click
[URL]/?_escaped_fragment_=/api/Titanium.UI.Label-method-add
[URL]/?_escaped_fragment_=/api/Titanium.UI.Label-property-children

This one should return the entire page:
[URL]/?_escaped_fragment_=/api/Titanium.UI.Label