Clean-up to various pieces of Perl code we have.
* ab/perl-fixes:
perl Git::LoadCPAN: emit better errors under NO_PERL_CPAN_FALLBACKS
Makefile: add NO_PERL_CPAN_FALLBACKS knob
perl: move the perl/Git/FromCPAN tree to perl/FromCPAN
perl: generalize the Git::LoadCPAN facility
perl: move CPAN loader wrappers to another namespace
perl: update our copy of Mail::Address
perl: update our ancient copy of Error.pm
git-send-email: unconditionally use Net::{SMTP,Domain}
Git.pm: hard-depend on the File::{Temp,Spec} modules
gitweb: hard-depend on the Digest::MD5 5.8 module
Git.pm: add the "use warnings" pragma
Git.pm: remove redundant "use strict" from sub-package
perl: *.pm files should not have the executable bit
These are original scripted implementations, kept primarily for their reference value to any aspiring plumbing users who want to learn how pieces can be fit together.