Specifiy both source ant target Java versions
...when compiling Java code. Since `stx:libjava` only supports Java 7,
make sure all code is compiled targeting Java 7.
This directory contains eXept's copy of stx:libjava.
Main repository is at
https://bitbucket.org/janvrany/stx-libjava
This copy may or may not be up-to-date.