Better face mapping for black/white PostScript printers.

Better face mapping for black/white PostScript printers.
Check if mark is active when printing a region.  Doc fix.
(ps-print-version): New version number (6.5.5).
(ps-print-color-p): Customization fix.
(ps-black-white-faces): New option.
(ps-black-white-faces-alist): New internal var.
(ps-count-lines-preprint, ps-print-preprint-region): New funs.
(ps-print-region, ps-print-region-with-faces, ps-nb-pages-buffer)
(ps-nb-pages-region): Interactive fix.
(ps-extend-face-list, ps-extend-face, ps-setup, ps-begin-job)
(ps-face-attributes, ps-generate-postscript-with-faces): Code fix.