Filter xml header from facelets in the response writer

Facelets writing out the xml header into the response writer
See also http://java.net/jira/browse/JAVASERVERFACES_SPEC_PUBLIC-696

The xml header declaration inside the HTML output sometimes makes problems with internet explorer.

To avoid performance degression we should filter exacly to this string: <?xml version="1.0" encoding="UTF-8"?>
So we have the possiblilty to declare the source code correctly as long as the application uses UTF-8.