This corrects some errors in the handling of initializing variables across SAVEVM, LOGOUT, SYSOUT and MAKESYS.
This is all now handled by MEDLEY-INIT-VARS (function and variable) which is called as an EVENTFN.
BEFOREMAKESYS (invoked by ENDLOADUP) clears the variables to a default setting (all directories are just {DSK}).
The other "BEFORE" events save away the current values of the variables in MEDLEY-INIT-VARS.
In order to get this to work it was necessary to change a hack for deciding where to find EXPORTS.ALL and WHEREIS.HASH. Now if you do `./scripts/loadup-all.sh` to make a full, lisp sysouts, exports.all and whereis.hash it will still build the sysouts in tmp/ but will also "link" new versions in loadups (and library for exports.all). This replaces the previous hack scanning the sysout name for "tmp/".
MEDLEY-INIT-VARS had been called both by the AROUNDEXITFN and AFTER*FORMS.
