Code modernising (#8)

* Applied some code conventions, used more current language features which should improve readability and making it easier to re-factor / modify. Also fixed some typos in documentation.
* Changes based on PR conversation for the SystemInfo
* Some modifications due to conversations on the PR, especially I removed the FlagsAttribute on the BalloonFlags.
* Removed Silverlight targeting in code.

Hardcodet.NotifyIcon.Wpf/Source/Windowless Sample/DelegateCommand.cs

@@ -0,0 +1,30 @@
+using System;
+using System.Windows.Input;
+
+namespace Windowless_Sample
+{
+    /// <summary>
+    /// Simplistic delegate command for the demo.
+    /// </summary>
+    public class DelegateCommand : ICommand
+    {
+        public Action CommandAction { get; set; }
+        public Func<bool> CanExecuteFunc { get; set; }
+
+        public void Execute(object parameter)
+        {
+            CommandAction();
+        }
+
+        public bool CanExecute(object parameter)
+        {
+            return CanExecuteFunc == null  || CanExecuteFunc();
+        }
+
+        public event EventHandler CanExecuteChanged
+        {
+            add { CommandManager.RequerySuggested += value; }
+            remove { CommandManager.RequerySuggested -= value; }
+        }
+    }
+}