[whatwg] Notes from IRC

[Adam Barth]

<Hixie> for Referer it looks like I defined everything except the bit
that actually invokes Referer :-)
<Hixie> search for "source browsing context"
<Hixie> the Referer is "the document's current address" of the "source
browsing context"'s "active document"
<Hixie> but apparently that sentence is missing
<Hixie> abarth_: if you do mail me, remind me to add that sentence