Previously, manual meta-data were added to the existing set of entries
which could lead to duplicates if a manual entry is meant to complement
a property that is detected via the processor.
We now match the name and type of the item against the auto-detected
entries. If no match is found, we add the extra entry as we did before.
If a match is found we override the description, default value and
deprecation information.
Closes gh-3562
Stephane Nicoll
35875c7f08