Refactoring visibility related events

1. remove unnecessary events from MainViewModel
2. remove usage of Obsolete api (show, hide etc)
3. fix space problem in #660
4. part of #486
5. fix up/down key bug introduced in 92b7ca6a1bafd254e39ee92812ff691906cd85c1
6. fix #678

Wox.Infrastructure/Logger/Log.cs

@@ -3,6 +3,7 @@ using System.IO;
 using NLog;
 using NLog.Config;
 using NLog.Targets;
+using Wox.Infrastructure.Exception;
 
 namespace Wox.Infrastructure.Logger
 {