lib/Tools/getenv
1997-04-22 wenzelm 1997-04-22 removed -norc;
1997-03-05 wenzelm 1997-03-05 improved DESCRIPTION;
1997-03-05 wenzelm 1997-03-05 added -a, -b options; multiple VARNAMES;
1996-12-09 wenzelm 1996-12-09 added -norc option;
1996-12-04 wenzelm 1996-12-04 *** empty log message ***
1996-12-02 wenzelm 1996-12-02 getenv: get value from Isabelle settings.