Finalize hopefully (mobile) sharing LBB over email.  Added code in
sharelittlebluebirdoveremail-nofooter.html to present yes/no buttons
after the user clicks share, to give the user the opportunity to share
with someone else.

On both yes and no buttons, we reset the form to its pristine state and
clear out the model so that the next time the user comes to this page,
the fields will be empty.