dev-java/oracle-jdk-bin: awt flag, nsplugin, javapackager

dev-java/oracle-jdk-bin: awt flag, nsplugin, javapackager

 * Change awt USE flag to !headless-awt
 * Install nsplugin to /usr/lib/nsbrowser/plugins in line with
   eselect-java and icedtea-web changes
 * Don't install javapackager unless javafx is enabled (#565828)

Sorry for changing the X/awt flag again but icedtea upstream preferred
the term headless, which is technically more accurate than awt, so I
compromised and went with headless-awt. This isn't icedtea but
consistency is king and I may apply this flag to virtual/jre one day.

Package-Manager: portage-2.2.26