Allows GL, xcb, xkeyboard-config to reach out into their dist/ directory,
and kdrive to reuse the xserver material (might be smarter to multi-package
xserver/kdrive ? though kdrive is not exactly quick to build)
pieces to try to compile directly from cvs (but xenocara needs to
stop reaching out in share/mk for that to work)
move xmessage to necessary build components, as some windowmaker widget
tests for its presence.