Take advantage of Wekbit speech input

Take advantage of Wekbit speech input

The x-webkit-speech attribute enables speech input on current versions
of Chrome. It's a frill, and I'm not sure we really want entire
libraries of patrons mumbling to themselves more than we already have,
but it's a low-cost frill so let's take advantage of it.

Signed-off-by: Dan Scott <dscott@laurentian.ca>
Signed-off-by: Dan Scott <dan@coffeecode.net>