perlcritic

We now have 80+ Perl files in our tree, and it's growing.  Some of those
files were originally written for Perl 4, and the coding styles and
quality are quite, uh, divergent.  So I figured it's time to clean up
that code a bit.  I ran perlcritic over the tree and cleaned up all the
warnings at level 5 (the default, least severe).

Testing guidelines:

- Many files are part of the regular build or test process.

- msvc files need to be tested separately.  I tested as best as I could
on a non-Windows system.

- There are a couple of one-offs in contrib and src/test that need to be
run manually.

- The stuff under utils/mb/Unicode/ has a makefile that is not part of
the normal build process.  I'll send in a few more patches to that in a
separate message that should help testing.

To install perlcritic, run

    cpan -i Perl::Critic

and then run

    perlcritic .

at the top of the tree (or a subdirectory).