Add XA classes to OSGi manifest headers.  Also generate OSGI headers for the default JAR, we were only generating OSGi headers for the complete JAR.
Add XA classes to OSGi manifest headers.  Also generate OSGI headers for
the default JAR, we were only generating OSGi headers for the complete JAR.

jesperpedersen/pgjdbc-ng,brettwooldridge/pgjdbc-ng,jesperpedersen/pgjdbc-ng,gregb/pgjdbc-ng,gregb/pgjdbc-ng,frode-carlsen/pgjdbc-ng