LP#1319964 "Summaries & More" displays improperly in TPAC

Commit 14eb3d30 added HTML-escaping of OPAC extras display
labels, meaning that if an ampersand in such a label is
desired, it should be entered in the template just as an ampersand.

Signed-off-by: Michael Peters <mpeters@emeralddata.net>

[Amended original commit to tweak message and remove unecessary changes
 to .po files, which are rebuilt when a release is rolled.]

Signed-off-by: Galen Charlton <gmc@esilibrary.com>