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).

On Windows  when building MSI, the original application name was 
determined by looking into the /app dir for a ".cfg" file.

The problem was that:

  - There may be application files with ".cfg" extension.

  - There may be multiple ".cfg" files due to --add-launcher option(s)

Instead we create an "<application name>.id" in the root of the 
app-image , to insure we can derive application name from app-image.

[1] https://bugs.openjdk.java.net/browse/JDK-8230920
[2] http://cr.openjdk.java.net/~herrick/8230920


Thanks

Andy,