Add runtime dependency to openjfx-dialogs
Removing unused test classes that were breaking the build on my machine.
As discussed in the controlsfx-dev mailing list, the old dialogs API is now deprecated, and will be replaced by the official JavaFX 8u40 API, as well as our own extensions.
This is phase 1: deprecation of all old API.
Deprecate ButtonBar also.
Fix gradle build script
Import command links, wizard and font selector dialogs based on new JavaFX 8u40 API.
Updated old dialogs samples and added new dialogs sample.