Ability to update settings. Take effect on next reboot.

API/Entities/ServerSetting.cs

@@ -7,7 +7,7 @@ namespace API.Entities
     public class ServerSetting : IHasConcurrencyToken
     {
         [Key]
-        public string Key { get; set; }
+        public ServerSettingKey Key { get; set; }
         public string Value { get; set; }
 
         [ConcurrencyCheck]

API/Entities/ServerSettingKey.cs

@@ -0,0 +1,10 @@
+namespace API.Entities
+{
+    public enum ServerSettingKey
+    {
+        TaskScan = 0,
+        CacheDirectory = 1,
+        TaskBackup = 2,
+        LoggingLevel = 3
+    }
+}