LP#1452352: fix generation of locale-specific RO object fetchers

LP#1452352: fix generation of locale-specific RO object fetchers

The TPAC R/O object cache is now keyed by locale.  This
fixes an issue where an OPAC session that starts in one
locale and gets switched to another could see (e.g.)
format labels for the original locale.

The issue fixed by this patch can be most readily reproduced
as follows:

[1] Enable both the en-US and fr-CA locales. Make sure
    that there are some translations for record format
    coded values in place as well.
[2] Run Apache in single-process mode
    (e.g., ". /etc/apache2/envvars && apache2 -X")
[3] Visit a record details page in the en-US locale. Note
    the label associated with the record format.
[4] Change the locale to fr-CA. Note that the label is
    still the English version.

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
Signed-off-by: Mike Rylander <mrylander@gmail.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>