Removed Chinese artifacts from Rare Artifact trait because end game there really are too many of them for it to be really rare.

Ingredients no longer marked with Artifact trait.

Changed flag for rare artifacts from Hermetic flag to Book or Invention flags, as hermetic ingredients ended up giving lots of rare artifact traits when it's a relatively common artifact.

Added "Rare Artifact" trait that shows on people with Heremetic/Religious/Rare/Very Rare flagged artifacts.
Changed trigger to owning 1 or more artifact rather then searching for flags.