Fix log format for http server and http channel objects

I set log level to `blather` and then I access to http server `http://127.0.0.1:9001/`.
Next, I check the log file /tmp/supervisord.log  and it has the following lines:
(omitted date and time)
```
BLAT read event caused by <socket._socketobject object at 0x7fcb6ed6a750>
BLAT read event caused by <socket._socketobject object at 0x7fcb6ed2d590>
BLAT read event caused by <socket._socketobject object at 0x7fcb6ed2d590>
BLAT write event caused by <socket._socketobject object at 0x7fcb6ed2d590>
```
I think that the above lines don't make sense because they did not show object's module name and class name. They should show as follows:
```
BLAT read event caused by <supervisor.http.supervisor_af_inet_http_server listening :9001 at 0x7fccaad59560>
BLAT read event caused by <supervisor.http.deferring_http_channel connected 127.0.0.1:47391 at 0x7fccaabe1320 channel#: 0 requests:0>
BLAT read event caused by <supervisor.http.deferring_http_channel connected 127.0.0.1:47391 at 0x7fccaabe1320 channel#: 0 requests:1>
BLAT read event caused by <supervisor.http.deferring_http_channel connected 127.0.0.1:47391 at 0x7fccaabe1320 channel#: 0 requests:2>
```