Add content type header for feed page
Add content type header for feed page

Added text/xml header for page which generates posts feed.

wojtekn/magehero,wojtekn/magehero,kalenjordan/magehero,kalenjordan/magehero,kalenjordan/magehero,kalenjordan/magehero,wojtekn/magehero,wojtekn/magehero