RFR 8160089: jshell tool: use new double-dash long-form command-line options

[Robert Field]

Updated --
   * No changes to non-default property files (thanks Jan)
   * Better checking for conflicting options
   * Better testing including of compound options and conflicting options

Please review....

Bug:
     https://bugs.openjdk.java.net/browse/JDK-8160089

Webrev Langtools:
     http://cr.openjdk.java.net/~rfield/8160089v1.webrev/

Webrev JDK:
     http://cr.openjdk.java.net/~rfield/8160089_jdkv0.webrev/

Thanks,
Robert