Changes to support different javac version

Dear Eric


The javac compiler settings are now configurable in ant.settings.
Not all <javac> tasks in build.xml had the same attributes set.

In particular, not specifying the encoding property reveals a usage of the currency sign (http://www.fileformat.info/info/unicode/char/a4/index.htm) in both jas.MethodHandleCP (line 27) and jas.InvokeDynamicCP (line 28).