Merge pull request #128 from avsm/master

tiny build cleanup and sync CHANGES
has_body:t -> bool should return [`Yes|`No|`Unknown]

The convention that is being copied is core's Sys.is_file/directory
function. This fixes the issue where the lwt client will not read
responses that don't specify the content length
Merge pull request #129 from rgrinberg/maybe_body

has_body:t -> bool should return [`Yes|`No|`Unknown]
sync CHANGES