Semicolon-free named entities aren't always parse errors.

`&Abreve` [isn't a named character reference](http://www.whatwg.org/specs/web-apps/current-work/multipage/named-character-references.html#named-character-references), but neither is it a parse error. Section [12.2.4.69 Tokenizing character references](http://www.whatwg.org/specs/web-apps/current-work/multipage/tokenization.html#tokenizing-character-references) says:

> Consume the maximum number of characters possible, with the consumed characters matching one of the identifiers in the first column of the named character references table (in a case-sensitive manner).
> 
> If no match can be made, then no characters are consumed, and nothing is returned. In this case, if the characters after the U+0026 AMPERSAND character (&) consist of a sequence of one or more alphanumeric ASCII characters followed by a U+003B SEMICOLON character (;), then this is a parse error.

No match is made, so nothing is consumed, and nothing is returned (good so far). And the characters after the ampersand do not consist of "a sequence of one or more alphanumeric ASCII characters followed by a U+003B SEMICOLON character (;)" because there's no semicolon. So I believe there is no parse error.

(Many other tests in this suite do the same thing. I'll happily add fixes for them to this pull request if you agree that they're in error.)