Allow users to search for nothing without an error.
Support for when Clean URL's is disabled.

Image paths can't use the 'q' parameter they must be absolute for apache to
serve them.
Hide the search results popup using a fade.

Bug in the use of "this" in a new context.
Reset tag level CSS rules set by BookReader.css
Center the display of search progress modal dialog box.

Previously it wasn't be centered for sites whose theme did not make the content
section of the site positioned relatively.