Clearing custom field values

The logic for editing CustomFieldValues in
share/html/Admin/CustomFields/Modify.html in 3.6.1

doesn’t allow for setting values to “”. That might be
alright for the name and description, but it’s a nuisance
if you put something in the Category field by mistake, and
can’t get it cleared out. (I speak from experience …)

This patch should fix that. Along the way, it also clear a few of the
rampant “undefined value” warnings.

Harry

values-modify.patch (2 KB)