8u40 Review Request: [EnsembleApp] Add dialogs sample to Ensemble

[Morris Meyer]

Folks,

Could you please review the new Dialog app for Ensemble8?

Thanks much!

        --mm

WEBREV - http://cr.openjdk.java.net/~morris/RT-39121.01
BUG - https://javafx-jira.kenai.com/browse/RT-39121