Combine FolderLinks and DirectoryIndicator into FileSystemPlugin

cc @aaroncampf

Wox.Infrastructure/Storage/UserSettings/FolderLink.cs

@@ -2,9 +2,16 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
+using Newtonsoft.Json;
 
 namespace Wox.Infrastructure.Storage.UserSettings {
 	public class FolderLink {
+        [JsonProperty]
 		public string Path { get; set; }
-	}
+
+	    public string Nickname
+	    {
+	        get { return Path.Split(new char[] { System.IO.Path.DirectorySeparatorChar }, StringSplitOptions.None).Last(); }
+	    }
+    }
 }