Summary
-------

Change the standard doclet so that by default, it does not generate support for frames.

Problem
-------

In times past, to allow for navigation within API documentation, the standard doclet presented 
indexes in frames on the left side of the window to allow classes, packages and (more recently)
modules to be selected for display in the main body of the window.

More recently, the doclet now supports a "search" feature, which provides a more versatile
way of finding items to view. Separately, the doclet is moving towards using HTML 5 (only),
and the basic support for frames in HTML 5 is less than it was in HTML 4.

The long term goal is to abolish the use of frames for navigation with API documentation,
in favor of better alternative mechanisms. In JDK 9, some changes were made in that direction:

* Two new options were added: `--frames` and `--no-frames`, to control whether or
not support for frames was included in the generated documentation. If neither was
specified, the default behavior was to generate support for frames.

* Even when support for frames was included in the generated documentation, 
frames were not _displayed_ by default; the reader could enable or disable them
by clicking on links, labelled `FRAMES` and `NO FRAMES`.

* The JDK API documentation allowed the generation of frames, allowing the
reader to enable them, using the `FRAMES` link.

The next step towards eliminating the use of frames is to make the default behavior
be equivalent to specifying the `--no-frames` option.


Solution
--------

Change the default behavior of the doclet so that support for frames
is not included in the generated API docs. 

The JDK API documentation will use the default behavior, which means it will
no longer be possible for the reader to enable the use of frames when viewing
the standard JDK API documentation.

Specification
-------------

The relevant lines from `javadoc -help` are these:

    --frames      Enable the use of frames in the generated output (default)
    --no-frames   Disable the use of frames in the generated output

The word "`(default)`" will be moved to the second line, as follows:

    --frames      Enable the use of frames in the generated output
    --no-frames   Disable the use of frames in the generated output (default)

In addition, when the `--frames` option is specified explicitly, a warning
will be produced indicating that support for frames will be removed in a future
release.