添加opencv最新库中以来的xfeatured下载文件，cmake使用
资源文件列表
xfeatures2d/boostdesc_bgm.i , 14852
xfeatures2d/boostdesc_bgm_bi.i , 14864
xfeatures2d/boostdesc_bgm_hd.i , 7832
xfeatures2d/boostdesc_binboost_064.i , 138093
xfeatures2d/boostdesc_binboost_128.i , 275322
xfeatures2d/boostdesc_binboost_256.i , 549754
xfeatures2d/boostdesc_lbgm.i , 426280
xfeatures2d/vgg_generated_120.i , 1257733
xfeatures2d/vgg_generated_48.i , 773330
xfeatures2d/vgg_generated_64.i , 915012
xfeatures2d/vgg_generated_80.i , 1012932