patch against r49247
Currently it's difficult to effectively customise the appearance of the notice that displays when previewing a page; the h2 "preview" header (and the "previewconflict" header when it appears) is unidentified and appears outside the <div class="previewnote"> that contains the "remember this is only a preview" message. Changes in this patch:
- assign IDs for both h2s so they can be identified individually
- move both <h2>s inside the "previewnote" div so it forms a clearer semantic grouping; move the "text-indent:3em" CSS rule to the inner <p> so it doesn't screw up the h2 indentation
- use an <hr> instead of a bottom margin; semantically clearer and probably better from an accessibility PoV.
attachment diff.txt ignored as obsolete