[PATCH] Abstract out a display-table-specific API (2)

[Stephen J. Turnbull]

mike.kupfer at xemacs.org writes:

 > Would the package-future.el that Stephen recently proposed be a good
 > place to put put-display-table and get-display-table, using
 > defun-when-void?

I think it's reasonable.  They should still be wrapped with a version
check.

I probably should use defun-when-void in the package-future.el defuns
I already have, rather than fboundp checks.