When unzipping an archive with `unzip` (e.g. `s3://vector-tiles-prod/20180326/a8a6c/all/11/333/744.zip`), files have `0000` permissions and need to be manually `chmod`'d by `root` to become readable. The fix appears to be to add ```python info.external_attr = 0755 << 16L ``` after https://github.com/tilezen/tilequeue/blob/4062c1a579bdf965a4ebc711f238d8b37de8b926/tilequeue/metatile.py#L54 Ditto for https://github.com/tilezen/tilequeue/blob/44b1aa6fefe4233d6cada0fe4a903c8dbfcc3f25/tilequeue/rawr.py#L537