Removed trailing comma in annotation array expressions

Oddly, the Java compiler used by default on Linux seems not to process
the trailing comma in annotation array expressions correctly,
producing an error for illegal start of expression, even though the
Java spec, section 9.7
(http://docs.oracle.com/javase/specs/jls/se5.0/html/interfaces.html#9.7
and http://docs.oracle.com/javase/specs/jls/se7/html/jls-9.html#jls-9.7)
allows the trailing comma.