AutoSuggest: Make directly clicking a suggestion initiate search

AutoSuggest: Make directly clicking a suggestion initiate search

Formerly, I thought it best not to do this, so that users could choose a
suggestion and refine their search term further, but that put the
widget's behavior at odds with that of certain ubiquitous search
engines.

Users can still highlight a suggestion and press tab to modify their
search further before submitting, if they wish (and if they know this or
figure it out somehow).

Signed-off-by: Lebbeous Fogle-Weekley <lebbeous@esilibrary.com>