Merge branch 'ab/send-email-perl'

* ab/send-email-perl: send-email: extract_valid_address use qr// regexes send-email: is_rfc2047_quoted use qr// regexes send-email: use Perl idioms in while loop send-email: make_message_id use "require" instead of "use" send-email: send_message die on $!, not $? send-email: use (?:) instead of () if no match variables are needed send-email: sanitize_address use qq["foo"], not "\"foo\"" send-email: sanitize_address use $foo, not "$foo" send-email: use \E***\Q instead of \*\*\* send-email: cleanup_compose_files doesn't need a prototype send-email: unique_email_list doesn't need a prototype send-email: file_declares_8bit_cte doesn't need a prototype send-email: get_patch_subject doesn't need a prototype send-email: use lexical filehandles during sending send-email: use lexical filehandles for $compose send-email: use lexical filehandle for opendir Conflicts: git-send-email.perl