this class is a singleton, nobody should call its constructor
give some info on the scripting engines when debugging is activated
be verbose when we mess with the selected progLang
verbose error message
Test the compilation process in our JUnit tests, for Java and Scala.
rerun po4a and ant-i18n
po4a.conf: fix paths after recent packages reorgs
move SourceFile classes to the session package
don't load the jarfile with javascript libs: we don't use it yet
make sure that scala compiles from the jar files
remove a debug output