Removed NioTSO client and server

- NioTSO client isn't needed because we're using RayLib
- Added FreeSO's API server to handle most backend operations

server/FSO.Server.Database/DA/Relationships/DbRelationship.cs

@@ -0,0 +1,12 @@
+namespace FSO.Server.Database.DA.Relationships
+{
+    public class DbRelationship
+    {
+        public uint from_id { get; set; }
+        public uint to_id { get; set; }
+        public int value { get; set; }
+        public uint index { get; set; }
+        public uint? comment_id { get; set; }
+        public uint date { get; set; }
+    }
+}

server/FSO.Server.Database/DA/Relationships/IRelationships.cs

@@ -0,0 +1,12 @@
+using System.Collections.Generic;
+
+namespace FSO.Server.Database.DA.Relationships
+{
+    public interface IRelationships
+    {
+        int UpdateMany(List<DbRelationship> entries);
+        List<DbRelationship> GetOutgoing(uint entity_id);
+        List<DbRelationship> GetBidirectional(uint entity_id);
+        int Delete(uint entity_id);
+    }
+}

server/FSO.Server.Database/DA/Relationships/SqlRelationships.cs

@@ -0,0 +1,84 @@
+using Dapper;
+using FSO.Server.Common;
+using MySql.Data.MySqlClient;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace FSO.Server.Database.DA.Relationships
+{
+    public class SqlRelationships : AbstractSqlDA, IRelationships
+    {
+
+        public SqlRelationships(ISqlContext context) : base(context)
+        {
+
+        }
+        public int Delete(uint entity_id)
+        {
+            return Context.Connection.ExecuteScalar<int>(
+                "DELETE FROM fso_relationships WHERE from_id = @entity_id OR to_id = @entity_id",
+                new { entity_id = entity_id }
+            );
+        }
+
+        public List<DbRelationship> GetBidirectional(uint entity_id)
+        {
+            return Context.Connection.Query<DbRelationship>(
+                "SELECT * FROM fso_relationships WHERE (from_id = @entity_id AND to_id < 16777216) OR (to_id = @entity_id AND from_id < 16777216)",
+                new { entity_id = entity_id }
+            ).ToList();
+        }
+
+        public List<DbRelationship> GetOutgoing(uint entity_id)
+        {
+            return Context.Connection.Query<DbRelationship>(
+                "SELECT * FROM fso_relationships WHERE from_id = @entity_id",
+                new { entity_id = entity_id }
+            ).ToList();
+        }
+
+        public int UpdateMany(List<DbRelationship> entries)
+        {
+            var date = Epoch.Now;
+            var conn = (MySqlConnection)Context.Connection;
+            int rows;
+            using (MySqlCommand cmd = new MySqlCommand("", conn))
+            {
+                try
+                {
+                    StringBuilder sCommand = new StringBuilder("INSERT INTO fso_relationships (from_id, to_id, value, `index`, `date`) VALUES ");
+
+                    bool first = true;
+                    foreach (var item in entries)
+                    {
+                        if (!first) sCommand.Append(",");
+                        first = false;
+                        sCommand.Append("(");
+                        sCommand.Append(item.from_id);
+                        sCommand.Append(",");
+                        sCommand.Append(item.to_id);
+                        sCommand.Append(",");
+                        sCommand.Append(item.value);
+                        sCommand.Append(",");
+                        sCommand.Append(item.index);
+                        sCommand.Append(",");
+                        sCommand.Append(date);
+                        sCommand.Append(")");
+                    }
+                    sCommand.Append(" ON DUPLICATE KEY UPDATE value = VALUES(`value`); ");
+
+                    cmd.CommandTimeout = 300;
+                    cmd.CommandText = sCommand.ToString();
+                    rows = cmd.ExecuteNonQuery();
+                }
+                catch (Exception e)
+                {
+                    return -1;
+                }
+                return rows;
+            }
+        }
+    }
+}