x86_64 is used as a baseline: the "x86_64" entry, whatever status it has,
is transformed into "all", and then the other entries in ARCHITECTURES
either dropped or rearranged appropriately.
* Mark x86_64 as tested.
* Fix COPYRIGHT years and LICENSE.
* Add the project's "COPYING" file as licenses/libXrender.
* Add README to $docDir.
* Move libXrender.txt to $developDocDir.