search: clicking on search result may not result in that page becoming the current page

[mangtronix]

Clicking on the search result in 1up may not result in that page becoming the current page (and thus being placed in the browser location).

e.g.
1. Load http://www.archive.org/stream/papersonbacterio00russrich#page/59/mode/1up/search/summary
2. Click "Page 69"
3. Page 69 becomes visible, but page 68 is at the top of the screen and /page/68 is in the browser location. Since the search result is centered and the *top* page is current there is a mismatch.

Expected:
Clicking a search result should always result in that page being the current one.

Proposed fix:
The center-most page in 1up should be the "current" page.