[10] RFR JDK-8156592:JFXPanel should use the new FocusEvent.getCause() API

[Prasanta Sadhukhan]

Hi All,

Please review a fix
http://cr.openjdk.java.net/~psadhukhan/fx/8156592/webrev.00/
for issue
https://bugs.openjdk.java.net/browse/JDK-8156592

More info in JBS.

Regards
Prasanta