openmpt: finalize function did not call parent's finalize

Signed-off-by: Carlos Rafael Giani <dv@pseudoterminal.org>
fixed format string type mismatches

Signed-off-by: Carlos Rafael Giani <dv@pseudoterminal.org>
enabled dumb&openmpt detailed mod caps for GStreamer 1.2.0 and newer

Signed-off-by: Carlos Rafael Giani <dv@pseudoterminal.org>