Fix for bugs:
[ 797401 ] infix should return string, not internal op
o Return the (first) operator string instead of the internal op.
o Apply to all operators such as prefix, postfix, nary, matchfix,
[ 1173788 ] assigning operators - case sensitivity problem
o Don't upcase the operator for prefix, postfix, nary, matchfix,
nofix, and infix.
o The error message for incorrect syntax printed the operator with the
o Some nicer indentation in a couple of functions.