improved "isabelle keywords" and "isabelle update_keywords" based on Isabelle/Scala, without requiring to build sessions first;
tuned signature;
#!/usr/bin/env bash
#
# Author: Makarius
#
# DESCRIPTION: update standard keyword files for Emacs Proof General
[ -e "$ISABELLE_HOME/Admin/build" ] && { "$ISABELLE_HOME/Admin/build" jars || exit $?; }
declare -a JAVA_ARGS; eval "JAVA_ARGS=($ISABELLE_BUILD_JAVA_OPTIONS)"
cd "$ISABELLE_HOME/etc"
"$ISABELLE_TOOL" java "${JAVA_ARGS[@]}" isabelle.Keywords update_keywords