[tcs-lc] Proposal: replace "Is parent/child of" with specific term

[Nozomi Ytow]

> Copy and paste without reading the result :-(

If I did so sorry, but 

> I meant 
> > >   sub-taxon-of, supra-taxon-of

why do you need both sub/supra and supra/sub pairs in different
direction?  That is what I wondered...

JMS