Fixed linking bug for streams that don't use both http/dataurisrc URIs.
Modification to stop playback when link is dropped.

We now send send an EOS and let the PLAYING_TO_PAUSED handle the
clean-up of the stream. In the past an error fetching a fragment
would not cause playback to actually stop.
Fix bug with attrib/value with no ending ',' and DOS linefeeds.

The original function handled attribute parsing poorly. It wasn't
clear if it handled attrib/value lacking a trailing ','.
Likewise, it did not handle DOS /r/n characters tacked on to the
end of the value of a terminating attribute. The new function
strips whitespace from the end of the value.