Fixed a bug in the processing of HTTP response headers

Response header values with leading or trailing whitespace were parsed incorrectly, even though the HTTP standard specifies that such whitespace should be ignored (http://www.ietf.org/rfc/rfc2616.txt - Section 4.2).
This change trims said whitespace from all HTTP reponse header values.

std/haxe/Http.hx

@@ -602,6 +602,7 @@ class Http {
 			var a = hline.split(": ");
 			var hname = a.shift();
 			var hval = if( a.length == 1 ) a[0] else a.join(": ");
+			hval = StringTools.ltrim( StringTools.rtrim( hval ) );
 			responseHeaders.set(hname, hval);
 			switch(hname.toLowerCase())
 			{