RFR: JDK-8225428: CLI change to remove "mode", rename to "package", and build only one target

[Andy Herrick]

Please review the jpackage fix for bug [1] at [2].

This is a fix for the JDK-8200758-branch branch of the open sandbox 
repository (jpackage).

JDK-8225428: CLI change to remove "mode", rename to "package", and build 
only one target

[1] https://bugs.openjdk.java.net/browse/JDK-8225428

[2] http://cr.openjdk.java.net/~herrick/8225428/webrev.01/ 
<http://cr.openjdk.java.net/%7Eherrick/8225428/>

/Andy