wishing fixes for "* glass"

wishing fixes for "* glass"

     The wishing code intended to make a wish for "blue glass" yield
a "worthless piece of blue glass" (and similarly for other specific
colors) but it didn't work right.  Also, wishing for "looking glass"
tripped up on that same code and didn't work either.  (Several other
permutations for worthless gems such as "worthless blue glass" and
"piece of glass" already do work.)