Bug 3756 Difference between original and local sysprefs

Bug 3756 Difference between original and local sysprefs

Amend Chris N. patch in order to display local sysprefs as the
difference between DB sysprefs and .pref files sysprefs.

As a side effect, local sysprefs editor displays also deprecated
sysprefs which is a feature from my point of view. For example,
GranularPermissions is displayed as a local syspref because it has been
removed recently from admin.pref but hasn't been yet removed from DB
(could be done later with a DB update).

Signed-off-by: Galen Charlton <gmcharlt@gmail.com>