editorial: inconsistent use of dfn in section names

[fippo]

In the image below some terminology shown in orange. In a very inconsistent and confusing way :-/

The DTMFSender uses this:

      <h3 id="h-rtcdtmfsender" resource="#h-rtcdtmfsender"><span property="xhv:role" resource="xhv:heading"><span class="secno">7.2 </span><dfn data-dfn-for="" data-dfn-type="dfn" id="dom-rtcdtmfsender" data-idl="" data-title="RTCDTMFSender"><code>RTCDTMFSender</code></dfn></span>
      </h3>

while the DTMFToneChangeEvent does not uses

      <h3 id="h-rtcdtmftonechangeevent" resource="#h-rtcdtmftonechangeevent"><span property="xhv:role" resource="xhv:heading"><span class="secno">7.3 </span>RTCDTMFToneChangeEvent</span>
     </h3>

The amount of work required to fix this might be tremendous :-/

[aboba]

@fippo I have fixed a few instances of the problem (dictionaries and enums).