more conservative Document_Model.init: avoid Document.Node.Clear due to change of token marker (e.g. due to change of jEdit mode properties);
clarified Isabelle.buffer_token_marker;
#
# Author: Makarius
#
# recode.pl - recode utf8 for ML
#
for (@ARGV) {
utf8::upgrade($_);
s/([\x80-\xff])/\\${\(ord($1))}/g;
print $_, " ";
}