refactor settings load/save

- load using LINUQ
- load on child settings on demond
- prevent error when plugin has been removed
- prevent settings loose when plugin has been removed

Pilz.Configuration/SettingsManager.cs

@@ -97,27 +97,33 @@ public class SettingsManager : ISettingsManager
         Instance.Reset();
     }
 
+    protected virtual ISettings CreateInstance()
+    {
+        return new Settings();
+    }
+
     protected virtual void CreateNewInstance()
     {
-        defaultInstance = new Settings();
+        defaultInstance = CreateInstance();
         defaultInstance.Reset();
     }
 
     protected virtual void LoadInternal()
     {
-        defaultInstance = JsonConvert.DeserializeObject<Settings>(File.ReadAllText(ConfigFilePath), CreateJsonSerializerSettings());
+        defaultInstance = CreateInstance();
+        defaultInstance.Load(CreateJsonSerializerSettings(), File.ReadAllText(ConfigFilePath));
     }
 
     protected virtual void SaveInternal()
     {
         SavingSettings?.Invoke(this, EventArgs.Empty);
-        File.WriteAllText(ConfigFilePath, JsonConvert.SerializeObject(defaultInstance, CreateJsonSerializerSettings()));
+        File.WriteAllText(ConfigFilePath, defaultInstance.Save(CreateJsonSerializerSettings()));
         SavedSettings?.Invoke(this, EventArgs.Empty);
     }
 
-    protected virtual JsonSerializerSettings CreateJsonSerializerSettings()
+    public virtual JsonSerializerSettings CreateJsonSerializerSettings()
     {
-        return new JsonSerializerSettings()
+        return new JsonSerializerSettings
         {
             Formatting = Formatting.Indented,
             TypeNameHandling = TypeNameHandling.Auto,