add abstract downloader
add abstract downloader

leoYY/galaxy,baidu/galaxy,bluebore/galaxy,baidu/galaxy,linyvxiang/galaxy,May2016/galaxy,sdgdsffdsfff/galaxy,ontologyzsy/galaxy,Kai-Zhang/galaxy,sdgdsffdsfff/galaxy,taotaowill/galaxy,fxsjy/galaxy,baidu/galaxy,sdgdsffdsfff/galaxy,ontologyzsy/galaxy,WangCrystal/galaxy,taotaowill/galaxy,szxw/galaxy,ontologyzsy/galaxy,fxsjy/galaxy,leoYY/galaxy,sdgdsffdsfff/galaxy,Kai-Zhang/galaxy,imotai/galaxy,bluebore/galaxy,ontologyzsy/galaxy,ontologyzsy/galaxy,imotai/galaxy,taotaowill/galaxy,leoYY/galaxy,szxw/galaxy,leoYY/galaxy,linyvxiang/galaxy,WangCrystal/galaxy,leoYY/galaxy,fxsjy/galaxy,linyvxiang/galaxy,imotai/galaxy,sdgdsffdsfff/galaxy,bluebore/galaxy,fxsjy/galaxy,linyvxiang/galaxy,linyvxiang/galaxy,szxw/galaxy,bluebore/galaxy,imotai/galaxy,fxsjy/galaxy,May2016/galaxy,imotai/galaxy,linyvxiang/galaxy,WangCrystal/galaxy,fxsjy/galaxy,szxw/galaxy,Kai-Zhang/galaxy,May2016/galaxy,bluebore/galaxy,leoYY/galaxy,fxsjy/galaxy,szxw/galaxy