Set extension with multiple accept based on order in parseExtensions, cu...

...rrently with multiple accepted types, no extension is set at all
Also when highest weight type is not in parseExtensions, but lower weighted types are, it now will set the lower one, instead of none.
Example: `$_SERVER['HTTP_ACCEPT'] = 'text/csv;q=1.0, application/json;q=0.8, application/xml;q=0.7'; `
would not change to json, while html is not even accepted here.