RFR:DK-8148457(Remove jdk.nashorn.tools.FXShell class and associated build.xml cruft)

[Srinivas Dama]

Hi,

Please review:
http://cr.openjdk.java.net/~sdama/8148457/webrev.00/ 
Bug: https://bugs.openjdk.java.net/browse/JDK-8148457 

I have verified all debug logs generated out of make targets for jdk9 forest build and 
nashorn ant targets.

Regards,
Srinivas