Issue70 profile names2

I just rewrote this. 
I think this could be clearer, e.g.:
To properly indicate use of DTLS, the &lt;proto&gt; field MUST
be set to "UDP/TLS/RTP/SAVPF", as specified in
 <xref target="RFC5764"/>, Section 8,
if the default candidate uses UDP transport, or "TCP/TLS/RTP/SAVPF",
as specified in <xref target="I-D.nandakumar-mmusic-proto-iana-registration"/>,
if the default candidate uses TCP transport.