in the original KDE implementation it was used along with Nepomuk,
but Nepomuk support was dropped yet some semantic URIs are still
used across the KDE applications (e.g. dolphin, gwenview) for
info other than size, date of modification, etc. thus keeping a
local static mini-hash for the kfileitem properties is not very
good as knfotranslator has its own hash mechanisms thus the
translator items got merged into the translator and is now fully
utilized hopefully dropping the memory usage a little bit of the
metadata provider.