Ported .Net Core commits:

hondacrx:
- Initial commit: Switch to .Net Core 2.0
- Fix build and removed not needed files
Fabi:
- Updated solution platforms.
- Changed folder structure.
- Change library target framework to netstandard2.0.
- Updated solution platforms again...
- Removed windows specific kernel32 function usage (Ctrl-C handler).

Source/Framework/Constants/AuctionConst.cs

@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2012-2017 CypherCore <http://github.com/CypherCore>
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+namespace Framework.Constants
+{
+    public enum AuctionError
+    {
+        Ok = 0,
+        Inventory = 1,
+        DatabaseError = 2,
+        NotEnoughtMoney = 3,
+        ItemNotFound = 4,
+        HigherBid = 5,
+        BidIncrement = 7,
+        BidOwn = 10,
+        RestrictedAccount = 13
+    }
+
+    public enum AuctionAction
+    {
+        SellItem = 0,
+        Cancel = 1,
+        PlaceBid = 2
+    }
+
+    public enum MailAuctionAnswers
+    {
+        Outbidded = 0,
+        Won = 1,
+        Successful = 2,
+        Expired = 3,
+        CancelledToBidder = 4,
+        Canceled = 5,
+        SalePending = 6
+    }
+}