Convert more constants from 'use constant' to 'Readonly my/our' syntax.

Increase use of Log::Log4perl, and get rid of messages to stdout/stderr.

Change Fuse::AFP to require Perl 5.10 or better, since I've already
dropped the 5.8 compat regex for AFP URL parsing.

Increase use of 'use English qw(-no_match_vars), to eliminate use of
cryptic symbol vars.

Get rid of more 'unless' usage, as recommended by perlcritic.

Eliminate more double-sigil derefs, per perlcritic.

Get rid of some camel-case vars, per perlcritic.

Use \A and \z instead of ^ and $ in some regexes, per perlcritic.

Drop unnecessary parens on builtin usage, per perlcritic.

Use q{} for strings with a lot of symbols, per perlcritic.

Use 'oct' operator instead of '0' preference for octal values, per perlcritic.

End more lists with trailing commas, per perlcritic.

Use m{} for more regexes, instead of //, per perlcritic.

Added dummy poll(), ioctl(), flock() and fallocate() implementations, and
implemented read_buf() and write_buf() for a (hopefully) zero-copy data
path.

Make more use of square brackets in pack masks.