feature request: library versioning

Stephen J. Turnbull writes: Here's the list... blink-paren provided by oa/edit-utils/blink-paren.el and oa/edit-utils/paren.el comint provided by libs/xemacs-base/comint.el and os/ilisp/comint-v18.el completer provided by os/ilisp/completer.el and os/ilisp/completer.new.el and os/ilisp/completer.no-fun.el devices provided by temacs and comm/w3/lisp/devices.el dll provided by libs/elib/dll-debug.el and libs/elib/dll.el eos-debugger provided by libs/Sun/sun-eos-debugger-extra.el and libs/Sun/sun-eos-debugger.el font provided by lisp/font.el and comm/w3/lisp/font.el il-luc19 provided by os/ilisp/illuc19.el and os/ilisp/ilxemacs.el lookup-select provided by mule/lookup/lisp/lookup-misc.el and mule/lookup/lisp/lookup-select.el md5 provided by temacs and comm/w3/lisp/md5.el menubar provided by temacs and lisp/menubar.el paren provided by oa/edit-utils/mic-paren.el and oa/edit-utils/paren.el pp provided by libs/xemacs-base/pp.el and libs/xemacs-devel/pretty-print.el rmail provided by comm/rmail/rmail.el and libs/mail-lib/rmail-mini.el sgml-mode provided by oa/psgml/psgml.el and oa/sgml/sgml-mode.el vc provided by prog/vc/vc.el and prog/vc-cc/vc.el vc-hooks provided by prog/vc/vc-hooks.el and prog/vc-cc/vc-hooks.el vm-search provided by comm/vm/vm-search.el and comm/vm/vm-search18.el and comm/vm/vm-search19.el w3-auto provided by comm/w3/lisp/docomp.el and comm/w3/lisp/w3-auto.el xpm-button provided by lisp/xpm-button.el and libs/xemacs-base/xpm-button.el