Two years ago I attended a picturesque outdoor wedding in August where the hot and humid weather had guests occasionally ducking into their cars to enjoy a blast of AC. Dyson’s new $99.99 handheld fan would have provided some much-needed relief then, although I’m not sure I would have been comfortable powering it up during the service or reception. The HushJet Mini Cool is as slim and sleek as Dyson’s recent thin vacuum and hair dryer , but it’s not quiet enough to earn the name “Hush.” That’s