gupnp av controlpoint renderer for images

[Chris Fahlman <chrisfahlman gmail com>]

Hi,

The following isn't really a bug, I guess. But I think it would be
useful, for testing purposes if anything else, to be able to use
gupnp-av-cp to view image files served by rygel.

When I try to view an image (eg, .png or .jpg) with gupnp-av-cp, the
image won't play.
Rygel prints an error message, e.g.:

Playbin-WARNING **: rygel-playbin-player.vala:202: Error from
GStreamer element playbin20: gstsouphttpsrc.c(1120):
gst_soup_http_src_parse_status ():
/GstPlayBin2:playbin20/GstURIDecodeBin:uridecodebin42/GstSoupHTTPSrc:source:
Not Acceptable (406), URL:
http://192.168.0.101:35914/MediaExport/i/NjU5NmJhZjkxMThlODhjOWE3ZmQxYzVhNjg2YzU3ZGY%3D