maintain classpath in more elementary manner: turn ISABELLE_CLASSPATH into -classpath option, so that all jars are covered by sun.misc.Launcher.AppClassLoader (e.g. relevant for loading add-on resources);
ignore $ISABELLE_JAVA_EXT -- do not change java.ext.dirs;
#
# Author: Makarius
#
# recode.pl - recode utf8 for ML
#
for (@ARGV) {
utf8::upgrade($_);
s/([\x80-\xff])/\\${\(ord($1))}/g;
print $_, " ";
}