v2.00

    Automatically lowercase the changefreq when loading invalid sitemaps
        (Requested in GH#5 Case insensitive values, by rkleemann)
    Ignore comments from loaded XML files
        (GH#3 Sitemap with comments not working, by astuanax)
    Support Google sitemap video, image and mobile extensions
        (Requested in GH#4 Image, Video, and Mobile sitemaps/extensions, by ianmcorvidae)