add WHATWG change for end tag br and end tag p in foreign content
add WHATWG change for end tag br and end tag p in foreign content

Sigil-Ebook/sigil-gumbo,Sigil-Ebook/sigil-gumbo,Sigil-Ebook/sigil-gumbo,Sigil-Ebook/sigil-gumbo,Sigil-Ebook/sigil-gumbo