Add a JavaDoc option to avoid web fonts being included in generated documentation.

With JDK-8324774, DejaVu web fonts used by the default stylesheet will be included with documentation bundles generated by JavaDoc. While this will improve the consistency of API documentation across browsers and platforms, there are cases in which inclusion of web fonts may not be desirable:

    - Projects that use custom stylesheets which make use of other fonts than the ones used by the default stylesheet.

    - Test environments that invoke javadoc so often that the inclusion of web fonts negatively impacts performance or storage requirements.