If an "index.lua" or "index.html" doesn't exist in zip file or the
filesystem, and no redirects have been defined for it either, then
redbean will render a listing of the zip central directory content
only if the request uri points to the root path.
Buffering now has optimal performance, bugs have been fixed, and some
missing apis have been introduced. This implementation is also now more
production worthy since it's less brittle now in terms of system errors.
That's going to help redbean since lua i/o is all based on stdio.
See #97
