Log Message:
math/pari: clean up REPLACE_PERL

Two of the files now use autoconf to insert the correct Perl interpreter.

The dependency "pre-install: replace-interpreter" was useless since then
replace-interpreter would be run once in a direct "bmake update" or
"bmake install", and twice in bulk builds since they first run "bmake
build" and then "bmake install".  And even in the latter case, \ 
replacing
the interpreter twice had no effect since it was already replaced in the
configure phase.