Add reflection-warnings.pl used by cmp-reflect.sh script

I added cmp-reflect.sh script a few commits ago, but neglected to add
this Perl program that it uses.
Add Perl program reorder-namespaces.pl to ease comparison of lint.sh output

between runs where the namespaces are linted in different orders.  For
example, the namespace order for many projects changed when Clojure
1.6 changed its hash function.