HTTPRequest: withCredentials in XMLHttpRequest and manageCookies in AIR's URLLoader are not the same

HTML5 doesn't have the ability to disable cookies, as far as I can tell, but we can disable them on native targets.

src/lime/_internal/backend/native/NativeHTTPRequest.hx

@@ -236,7 +236,7 @@ class NativeHTTPRequest
 			curl.setOption(HEADERFUNCTION, curl_onHeader);
 		}
 
-		if (parent.withCredentials)
+		if (parent.manageCookies)
 		{
 			// an empty string means store cookies in memory
 			// cookies are stored only for the current session

src/lime/net/HTTPRequest.hx

@@ -41,6 +41,7 @@ public var timeout:Int;
 public var uri:String;
 public var userAgent:String;
 public var withCredentials:Bool;
+public var manageCookies:Bool;
 #if !doc_gen
 @:noCompletion private var __backend:HTTPRequestBackend;
 #end
@@ -57,6 +58,7 @@ public function new(uri:String = null)
 	method = GET;
 	timeout = #if lime_default_timeout Std.parseInt(Compiler.getDefine("lime-default-timeout")) #else 30000 #end;
 	withCredentials = false;
+	manageCookies = true;
 
 	#if !doc_gen
 	__backend = new HTTPRequestBackend();
@@ -166,6 +168,7 @@ public function load(uri:String = null):Future<T>
 	public var uri:String;
 	public var userAgent:String;
 	public var withCredentials:Bool;
+	public var manageCookies:Bool;
 	public function cancel():Void;
 }