...when generating "TRC variants"
When creating a new profile with different TRC from an existing
profile, keep all the original profile's description, model,
manufacturer and copyright strings around, but prefix them with "GIMP
from " or similar to indicate that they are different. Also make sure
we don't prefix strings with GIMP stuff multiple times when profiles
are generated repeatedly.
(cherry picked from commit 3cad4aa4c2)