RFR 8080598: Javadoc warnings in Global.java after lazy initialization

[A. Sundararajan]

Please review http://cr.openjdk.java.net/~sundar/8080598/ for 
https://bugs.openjdk.java.net/browse/JDK-8080598

In addition to IDE warnings for Global.java, I have fixed 2 unrelated 
javadoc errors elsewhere. To avoid having
to fix broken docs later, I'm adding "javadoc" target as "test" target 
dependency.  This will at least ensure error free
javadoc comments.

Thanks,
-Sundar