Introduces two Phantom Types, Fresh and Streaming, which indicate the status
of a Response.
Response::start translates an Response<Fresh> into a
Response<Streaming> by writing the StatusCode and Headers.
Response<Fresh> allows modification of Headers and StatusCode, but does
not allow writing to the body. Response<Streaming> has the opposite privileges.
This fixes an unsafe transmute that could cause use-after-frees
on collision resolution in the headers hash and avoids allocating
for cases where it is not necessary.
Fixes#12
This allows downstream users to have total control of their concurrency
strategy, while also exposing a very nice, streaming interface for frameworks
to build on.
This also resolves issues surrounding the use of IoResult as the return type
of Handler::handle, because handlers now have complete control over how to
handle internal failure.
Fixes#3Fixes#4
