[Patch21.5] Find a relative package root at runtime

Attached is a patch which allows 21.5 to find a package tree in ../xemacs-packages. This is similar to the patch I applied to 21.4 - http://list-archive.xemacs.org/xemacs-patches/200512/msg00137.html The purpose of this patch is to support XEmacs 21.5 finding its package directories at run-time. This is necessary to create a Windows native setup kit for 21.5, as exists now for 21.4, c.f. ftp://ftp.xemacs.org/pub/xemacs/windows/XEmacs%20Setup%2021.4.19.exe . One thing to note about this patch is that it changes xemacs.mak so that it does not use the now-deprecated PACKAGE_PATH mechanism by default. That mechanism is still supported (if you specify PACKAGE_PATH or PACKAGE_PREFIX in config.inc you can still force a particular package path into the executable). This patch also comments out the default usage of PACKAGE_PREFIX in config.inc.samp. Strictly speaking, this is not entirely required for my needs (I could just build a kit without PACKAGE_PREFIX), but since that mechanism is deprecated, I thought we shouldn't be encouraging people to use it. Comments please. I will commit this patch in a few days if I don't hear any objections. Regards, Vin -- Whoever you are, no matter how lonely, the world offers itself to your imagination, calls to you like the wild geese, harsh and exciting-- over and over announcing your place in the family of things. Mary Oliver