Introduced a very simple "singleton" service-locator, which allowed for a removal of specific implementations which were very limited. With this it's easier to access dependencies.

GreenshotPlugin/Interfaces/Plugin/IGreenshotPlugin.cs

@@ -0,0 +1,25 @@
+using System;
+
+namespace Greenshot.Plugin
+{
+    /// <summary>
+    /// This defines the plugin
+    /// </summary>
+    public interface IGreenshotPlugin : IDisposable {
+        /// <summary>
+        /// Is called after the plugin is instantiated, the Plugin should keep a copy of the host and pluginAttribute.
+        /// </summary>
+        /// <returns>true if plugin is initialized, false if not (doesn't show)</returns>
+        bool Initialize();
+
+        /// <summary>
+        /// Unload of the plugin
+        /// </summary>
+        void Shutdown();
+
+        /// <summary>
+        /// Open the Configuration Form, will/should not be called before handshaking is done
+        /// </summary>
+        void Configure();
+    }
+}