Better handling of close detection.
Better handling of close detection.

Instead of waiting for write failure (initial writes can take a while), use a
CloseNotifier to see when the HTTP request will fail.

google/stenographer,nbareil/stenographer,gconnell/stenographer,nbareil/stenographer,dcode/stenographer,google/stenographer,google/stenographer,gconnell/stenographer,gconnell/stenographer,nbareil/stenographer,dcode/stenographer,dcode/stenographer