Doc fix, duplex and setpagedevice configuration.

Doc fix, duplex and setpagedevice configuration.
(ps-print-version): New version number (4.2).
(ps-spool-config, ps-spool-tumble): New vars.
(ps-print-prologue-1): Changed to defconst, adjust PostScript
programming, new PostScript procedure to handle errors.
(ps-print-prologue-2): Changed to defconst.
(ps-print-duplex-feature): New const: duplex and tumble setting.
(ps-setup, ps-begin-file): Fix funs.
(ps-boolean-capitalized): New fun.

Doc fix, n-up printing.
(ps-print-version): New version number (5.0).
(ps-page-dimensions-database): Added document media.
(ps-n-up-printing, ps-n-up-margin, ps-n-up-border-p, ps-n-up-filling)
(ps-page-order, ps-printing-region-p): New vars.
(ps-n-up-printing, ps-n-up-filling, ps-header-sheet, ps-end-job): New
funs.
(ps-page-dimensions-get-media, ps-n-up-landscape, ps-n-up-lines)
(ps-n-up-columns, ps-n-up-missing, ps-n-up-xcolumn, ps-n-up-ycolumn)
(ps-n-up-xline, ps-n-up-yline, ps-n-up-repeat, ps-n-up-end)
(ps-n-up-xstart, ps-n-up-ystart): New macros.
(ps-print-begin-sheet-hook): New hook.
(ps-boundingbox-re, ps-n-up-database, ps-n-up-filling-database): New
const.
(ps-setup, ps-begin-file, ps-get-buffer-name, ps-begin-job)
(ps-end-file, ps-dummy-page, ps-generate): Fix funs.
(ps-print-prologue-1): Adjust PostScript programming for n-up printing.
(ps-count-lines): Changed to defun.
(ps-header-page): Changed to defsubst, fix fun.
(ps-printing-region): Doc fix, adjust programming code.
(ps-output-boolean, ps-background-pages, ps-background-text)
(ps-background-image, ps-background, ps-get-boundingbox): Adjust
programming code.

Doc fix, better customization.
(ps-print-region-function, ps-number-of-columns, ps-spool-tumble)
(ps-print-color-p, ps-printing-region-p, ps-n-up-database)
(ps-end-file): Doc fix.
(ps-setup, ps-begin-file): Fun fix.
(postscript): New group.
(ps-zebra-gray, ps-banner-page-when-duplexing): New vars.
(ps-print-prologue-1): Adjust PostScript programming.
(ps-print): Adjust group hierarchy.
(ps-print-n-up, ps-print-zebra, ps-print-background,
ps-print-printer)
(ps-print-page): New subgroups.
(ps-print-prologue-header, ps-printer-name, ps-lpr-command)
(ps-lpr-switches, ps-page-dimensions-database, ps-paper-type)
(ps-landscape-mode, ps-print-control-characters, ps-n-up-printing)
(ps-n-up-margin, ps-n-up-border-p, ps-n-up-filling, ps-zebra-stripes)
(ps-zebra-stripe-height, ps-print-background-image)
(ps-print-background-text, ps-spool-config): Adjust customization.
(dos-ps-printer): Definition eliminated.