* Add some more logging about what's going on.
* the 'new' hook has the length of the incoming chunk, but the chunk
  hasn't yet been consumed from the incoming stream. chunk_done is
  called when the chunk data is read.
* .. so, consume the chunk data from the stream as we read it.

This should fix the memory leaks I was seeing.
Start fleshing out the target request count for a given connection.

The mgr connection logic still doens't handle the underlying client going
away so that'll segfault.  But it does retry up to the limit now.
there's also something odd going on where a request doesn't make
progress and seems "stuck" without calling a finish notify.
I need to figure that one out.

Also, I think I do have to hook the request done hook, rather than
using chunks_done and request_fini as the hooks to start a new
request.  Hm.