(pmail-message-labels-p): Function moved from pmail.el and rewritten.

(pmail-message-labels-p): Function moved from pmail.el and rewritten.
(pmail-message-recipients-p): Likewise.
(pmail-message-regexp-p): Likewise.
(pmail-message-recipients-p-1): New subroutine.
(pmail-message-regexp-p-1): Likewise.
(pmail-summary-by-topic): Use pmail-simplified-subject.
Delete subject-re variable.
(pmail-message-subject-p): Total rewrite.
(pmail-message-senders-p): Total rewrite.
(pmail-new-summary-1): Call FUNCTION in the main Pmail buffer.
(pmail-get-summary): Doc fix.
(pmail-create-summary-line): Renamed from
pmail-get-create-summary-line, and major rewrite.
(pmail-get-summary-labels): Doc fix.
(pmail-create-summary): Major rewrite.  Construct line counts here.
(pmail-header-summary): Renamed from pmail-make-basic-summary-line.
Return list of two strings.
(pmail-summary-next-same-subject): Extract subjects and compare.
(pmail-summary-output): Renamed from pmail-summary-output-to-babyl-file.
Use pmail-output.
(pmail-summary-output-as-seen): Renamed from pmail-summary-output.
Use pmail-output-as-seen.
(pmail-summary-construct-io-menu): Use pmail-summary-output.