Fix bug on selected pages for printing. Use

Fix bug on selected pages for printing.  Use
`color-values' for Emacs 21.  Ensure fontification when jit-lock
is on.  Try to avoid warning messages when compiling.  Doc Fix.
(ps-print-version): New version number (6.3).
(ps-color-device): Use `color-values' to determine if device
supports color.
(ps-color-values): Try to use `x-color-values' when using XEmacs.
(ps-print-page-p): Changed from defsubst to defun.
(ps-page-number): Changed from defmacro to defun.
(ps-header-sheet, ps-header-page): Fix bug on selected pages for
printing.
(ps-print-ensure-fontified): Ensure fontification when jit-lock is
on.
(ps-end-file, ps-dummy-page): Funs eliminated.
(ps-print-color-scale): Changed default value.
(ps-page-n-up, ps-print-page-p): New internal vars.
(ps-print-preprint, ps-output, ps-begin-file, ps-begin-page)
(ps-plot-region, ps-generate, ps-end-job): Code fix.