This is an extension to evhttp. Without this, we cannot know that the client
closes the connection, and we keep pushing chunks while the underlying
evhttp_request has been freed, leading to a segfault.
iTunes and Roku devices do not encode + as %2B in the query string and
do not encode space as + either in the query string (though at least the
Roku encode space as %20 everywhere). This needs to be worked around or
browse queries fail to parse because + was decoded as space when the query
really needs a + character.
Transcoding is not supported yet.
In the current state of affairs, we will crash if the client closes the
connection before the tranfser is done. This is a limitation of evhttp,
it is not possible to detect this condition. This will need to be fixed
in evhttp.