Do not autofocus the search input field.

Autofocusing on the search field hijacks page scrolling with arrows and page up
and page down. If the search bar was only on one page, I could see it being
useful to autofocus, but it being on every page makes it feel like less of the
focus.
Merge pull request #308 from opscode/do_not_autofocus_search

Do not autofocus the search input field.