send-email: don't use Mail::Address, even if available

Using Mail::Address made sense when we didn't have a proper parser. We
now have a reasonable address parser, and using Mail::Address
_if available_ causes much more trouble than it gives benefits:

* Developers typically test one version, not both.

* Users may not be aware that installing Mail::Address will change the
  behavior. They may complain about the behavior in one case without
  knowing that Mail::Address is involved.

* Having this optional Mail::Address makes it tempting to anwser "please
  install Mail::Address" to users instead of fixing our own code. We've
  reached the stage where bugs in our parser should be fixed, not worked
  around.

Signed-off-by: Matthieu Moy <git@matthieu-moy.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-send-email.perl

@@ -155,7 +155,6 @@ sub format_2822_time {
 }
 
 my $have_email_valid = eval { require Email::Valid; 1 };
-my $have_mail_address = eval { require Mail::Address; 1 };
 my $smtp;
 my $auth;
 my $num_sent = 0;
@@ -490,11 +489,7 @@ my ($repoauthor, $repocommitter);
 ($repocommitter) = Git::ident_person(@repo, 'committer');
 
 sub parse_address_line {
-	if ($have_mail_address) {
-		return map { $_->format } Mail::Address->parse($_[0]);
-	} else {
-		return Git::parse_mailboxes($_[0]);
-	}
+	return Git::parse_mailboxes($_[0]);
 }
 
 sub split_addrs {