Required Sphinx extension setup function.

def setup(app):
    ''' Required Sphinx extension setup function. '''

    # These two are deprecated and no longer have any effect, to be removed 2.0
    app.add_config_value('bokeh_plot_pyfile_include_dirs', [], 'html')
    app.add_config_value('bokeh_plot_use_relative_paths', False, 'html')

    app.add_directive('bokeh-plot', BokehPlotDirective)
    app.add_config_value('bokeh_missing_google_api_key_ok', True, 'html')
    app.connect('builder-inited', builder_inited)
    app.connect('build-finished', build_finished)