[XHR] Editorial: typos

Section 2, OPEN: "During this state reqeust headers...", s/reqeust/request/

Section 2, setRequest() algorithm, step 3: "...the user agent must raise a  
SYNTAX_ERR and abort these steps", should say "...SYNTAX_ERR exception..."

After the send(data) algorithm: "if authentication fails...", s/if/If/

statusText of type DOMString, readonly: "It must be available when the  
state is RECEIVING or LOADED).", the ")" shouldn't be there

-- 
Simon Pieters