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/NotifyIconViewModel.cs

@@ -1,5 +1,4 @@
-using System;
-using System.Windows;
+using System.Windows;
 using System.Windows.Input;
 
 namespace Windowless_Sample
@@ -57,30 +56,4 @@ 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; }
-        }
-    }
 }