2010-04-17 ago improved ISABELLE_JAVA, based on THIS_JAVA of the actually running JVM;
2010-04-14 ago more precise treatment of UNC server prefix, e.g. //foo;
2010-03-30 ago adapted to Scala 2.8.0 Beta 1;
2010-03-29 ago adapted to Scala 2.8.0 Beta1 -- with notable changes to scala.collection;
2010-01-09 ago misc tuning;
2010-01-09 ago added find_files;
2010-01-04 ago Standard_System.raw_exec;
2010-01-02 ago Standard_System.raw_execute: optional cwd;
2009-12-28 ago ignore undefined environment;
2009-12-28 ago separate Standard_System (Cygwin/Posix compatibility) vs. Isabelle_System (settings environment etc.);