Changed design of monitors for better extensibility

MtApi/Monitors/Triggers/IMonitorTrigger.cs

@@ -0,0 +1,27 @@
+using System;
+
+namespace MtApi.Monitors.Triggers
+{
+    /// <summary>
+    /// Interface for triggers which can be used to trigger a <see cref="MtMonitorBase"/>.
+    /// </summary>
+    public interface IMonitorTrigger
+    {
+        /// <summary>
+        /// Event will be called if the trigger raised.
+        /// </summary>
+        event EventHandler Raised;
+        /// <summary>
+        /// Returns whether the trigger is started
+        /// </summary>
+        bool IsStarted { get; }
+        /// <summary>
+        /// Stops the trigger and prevents further calls of the <see cref="Raised"/> event.
+        /// </summary>
+        void Stop();
+        /// <summary>
+        /// Starts the trigger.
+        /// </summary>
+        void Start();
+    }
+}