Fix HTML escaping for localized strings in javascript.

There were a handful of other strings containing HTML in the javascript which
were localized with gettext, but then inserted into an underscore template in a
way that would escape the HTML. I've gone through all of the occurrences of
"gettext" and made sure that anything containing HTML tags is formatted using
<%= %> instead of <%- %>.

Testing done:
Checked the pre-commit and comment dialog UIs to verify the fixed text.

Reviewed at http://reviews.reviewboard.org/r/4469/