1. It's confusing. People think you click it to perform the search, then are surprised when it doesn't do that.
2. Now that the search results are displayed more clearly, there's really no need for a titles-only search option.
pulldown with "titles only" and "everything" radio buttons, defaulting to
"titles only".
* Wiki javascript code for submitting a search now sends a new titles_only
parameter according to what the user has selected in the search pulldown.
* controller.Notebooks.search() now takes a new titles_only boolean argument,
which does exactly what you would expect.