New feature:

New feature:
Automatic or manual collapsing and expanding of long pages.
Pages can be collapsed automatically according to a size threshold
set in the user preferences. Pages can be collapsed manually by clicking
the "Collapse" link in the TOC.

When a page is collapsed, only the intro & TOC are displayed. The
individual TOC lines link to section views, which can be individually edited
(classic section editing).

Section editing/viewing behavior has also been improved. When a section
with subsections is viewed or edited, all subsections are also loaded.

Known issues:
- After saving a section, we return to the full article view
rather than the section view, even if we previously were in section view
mode.
- Should work with Standard and Monobook, not tested with Cologne Blue yet.
- In Monobook, no backlink to the mother article is shown during section
viewing (Gabriel, can you fix that?)