- Add Margin option

- Add `Margin` property to `ITheme`
- Add `Stop` method to the `Plugin` API
- Add `DrawStringNoLeftPadding` and `MeasureStringNoLeftPadding` to `GraphicsExtentions`
- Convert most inbuilt components to plugins.
- Minor code improvements

src/DesktopMagicPluginAPI/Plugin.cs

@@ -49,6 +49,13 @@ namespace DesktopMagicPluginAPI
         {
         }
 
+        /// <summary>
+        /// Occurs once when the plugin gets deactivated.
+        /// </summary>
+        public virtual void Stop()
+        {
+        }
+
         /// <summary>
         /// Occurs when the <see cref="UpdateInterval"/> elapses.
         /// </summary>