LP#1301599 TPAC replace aria-label with title

LP#1301599 TPAC replace aria-label with title

As appropriate, replace aria-label attributes with traditional HTML
title attributes.

For ref, from the LP entry:

http://www.w3.org/TR/2013/WD-aria-in-html-20131003/#first-rule-of-aria-use

"If you can use a native HTML element [HTML5] or attribute with the
semantics and behaviour you require already built in, instead of
re-purposing an element and adding an ARIA role, state or property to
make it accessible, then do so."

Signed-off-by: Bill Erickson <berick@esilibrary.com>
Signed-off-by: Ben Shum <bshum@biblio.org>