RFR: JDK-8232919: If user installs msi and exe, two installations are found in Add/Remove

Sat Nov 2 00:06:07 UTC 2019

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).

Additionally:
- added support for `overrides.wxi` WiX source file in resource dir. 
Custom overrides.wxi can be used as a placeholder for overrides of 
default WiX variables defined by jpackage that control output msi.

- Alexey

[1] https://bugs.openjdk.java.net/browse/JDK-8232919

[2] http://cr.openjdk.java.net/~asemenyuk/8232919/webrev.00