RFR 8138643: nashorn ant build.xml javadoc, javadocapi targets are broken and netbeans makefile does not include shell sources

[Sundararajan Athijegannathan]

Please review http://cr.openjdk.java.net/~sundar/8138643/ for 
https://bugs.openjdk.java.net/browse/JDK-8138643

Thanks,
-Sundar