Fix for not working user login & creation

I had added:
* missing body for user creation request
* changed URI creation for login, because previous one didn't worked. Full url was setted as a path
* this commit also include changes from this pull request parse-community#5

lib/parse_user.dart

@@ -9,7 +9,7 @@ import 'parse_http_client.dart';
 class User implements ParseBaseObject {
   final String className = '_User';
   final ParseHTTPClient client = ParseHTTPClient();
-  String path = "/parse/classes/_User";
+  String path = "/classes/_User";
   Map<String, dynamic> objectData = {};
 
   static ParseUserData userData;
@@ -70,26 +70,44 @@ class User implements ParseBaseObject {
       objectData = {}..addAll(objectData)..addAll(objectInitialData);
     }
     _resetObjectId();
-    print(objectData);
-    final response = this.client.post("${client.data.serverUrl}$path",
+
+    Map<String, dynamic> bodyData = {};
+    bodyData["email"] = userData.username;
+    bodyData["password"] = userData.password;
+    bodyData["username"] = userData.username;
+
+    Uri tempUri = Uri.parse(client.data.serverUrl);
+
+    Uri url = Uri(
+        scheme: tempUri.scheme,
+        host: tempUri.host,
+        path: "${tempUri.path}$path"
+    );
+
+    final response = this.client.post(url,
         headers: {
           'X-Parse-Revocable-Session': "1",
         },
-        body: JsonEncoder().convert(objectData));
+        body: JsonEncoder().convert(bodyData));
+
     return response.then((value) {
       _handleResponse(value.body);
       return objectData;
     });
   }
 
   Future<Map<String, dynamic>> login() async {
-
-    Uri url = new Uri(
-        path: "${client.data.serverUrl}/parse/login",
-        queryParameters: {
-          "username": userData.username,
-          "password": userData.password
-        });
+    Uri tempUri = Uri.parse(client.data.serverUrl);
+
+    Uri url = Uri(
+      scheme: tempUri.scheme,
+      host: tempUri.host,
+      path: "${tempUri.path}/login",
+      queryParameters: {
+        "username": userData.username,
+        "password": userData.password
+      }
+    );
 
     final response = this.client.post(url, headers: {
       'X-Parse-Revocable-Session': "1",
@@ -102,7 +120,7 @@ class User implements ParseBaseObject {
 
   Future<Map<String, dynamic>> verificationEmailRequest() async {
     final response = this.client.post(
-        "${client.data.serverUrl}/parse/verificationEmailRequest",
+        "${client.data.serverUrl}/verificationEmailRequest",
         body: JsonEncoder().convert({"email": userData.emailAddress}));
     return response.then((value) {
       return _handleResponse(value.body);
@@ -111,7 +129,7 @@ class User implements ParseBaseObject {
 
   Future<Map<String, dynamic>> requestPasswordReset() async {
     final response = this.client.post(
-        "${client.data.serverUrl}/parse/requestPasswordReset",
+        "${client.data.serverUrl}/requestPasswordReset",
         body: JsonEncoder().convert({"email": userData.emailAddress}));
     return response.then((value) {
       return _handleResponse(value.body);