RFR: JDK-8230920 : jpackage problems when -input dir contains any files with "cfg" extension.

[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).

This fix replaces the practice we were using on windows to determine the 
application name, and name of additional launchers (by looking for 
".cfg" files in the app dir.

Instead we now add a file ".jpackage.args" to the root of the app-image, 
and record in that file all the arguments used to create the app-image.  
We later read that file to determine the original app name and any 
additional launcher names.

This change also fixes the shortcut creation on windows to create 
shortcuts (if so directed) for all launchers.

[1] https://bugs.openjdk.java.net/browse/JDK-8230920

[2] http://cr.openjdk.java.net/~herrick/8230920/webrev.01/

/Andy