Download larger data sets for various Bokeh examples.

def download(progress=True):
    ''' Download larger data sets for various Bokeh examples.

    '''
    data_dir = external_data_dir(create=True)
    print("Using data directory: %s" % data_dir)

    s3 = 'https://bokeh-sampledata.s3.amazonaws.com'
    files = [
        (s3, 'CGM.csv'),
        (s3, 'US_Counties.zip'),
        (s3, 'us_cities.json'),
        (s3, 'unemployment09.csv'),
        (s3, 'AAPL.csv'),
        (s3, 'FB.csv'),
        (s3, 'GOOG.csv'),
        (s3, 'IBM.csv'),
        (s3, 'MSFT.csv'),
        (s3, 'WPP2012_SA_DB03_POPULATION_QUINQUENNIAL.zip'),
        (s3, 'gapminder_fertility.csv'),
        (s3, 'gapminder_population.csv'),
        (s3, 'gapminder_life_expectancy.csv'),
        (s3, 'gapminder_regions.csv'),
        (s3, 'world_cities.zip'),
        (s3, 'airports.json'),
        (s3, 'movies.db.zip'),
        (s3, 'airports.csv'),
        (s3, 'routes.csv'),
        (s3, 'haarcascade_frontalface_default.xml'),
    ]

    for base_url, filename in files:
        _download_file(base_url, filename, data_dir, progress=progress)