Unhandled IOException after opening multiple files

[kkostov]

On windows 8.1 update 1, selecting multiple mkd files in file open dialog (to be opened simultaneously for editing) results in a System.IO.IOException exception causing the application to quit:

Application: MarkPad.exe Framework Version: v4.0.30319 Description: The process was terminated due to an unhandled exception. Exception Info: System.IO.IOException Stack: at System.IO.__Error.WinIOError(Int32, System.String) at System.IO.FileStream.Init(System.String, System.IO.FileMode, System.IO.FileAccess, Int32, Boolean, System.IO.FileShare, Int32, System.IO.FileOptions, SECURITY_ATTRIBUTES, System.String, Boolean, Boolean, Boolean) at System.IO.FileStream..ctor(System.String, System.IO.FileMode, System.IO.FileAccess, System.IO.FileShare, Int32, System.IO.FileOptions, System.String, Boolean, Boolean, Boolean) at System.IO.StreamWriter.CreateFile(System.String, Boolean, Boolean) at System.IO.StreamWriter..ctor(System.String, Boolean, System.Text.Encoding, Int32, Boolean) at System.IO.File.InternalWriteAllText(System.String, System.String, System.Text.Encoding, Boolean) at System.IO.File.WriteAllText(System.String, System.String, System.Text.Encoding) at MarkPad.Settings.FileSystemStorageSettingsStore.WriteTextFile(System.String, System.String) at MarkPad.Settings.JsonSettingsStoreBase.Save(System.String, System.Collections.Generic.Dictionary`2<System.String,System.String>) at MarkPad.Settings.SettingsProvider.SaveSettings[System.__Canon, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089] at MarkPad.Infrastructure.JumpListIntegration.OpenFileAsync(System.String) at MarkPad.Infrastructure.JumpListIntegration+<>cDisplayClass1.b0(System.Object) at System.Threading.ThreadHelper.ThreadStart_Context(System.Object) at System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean) at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean) at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object) at System.Threading.ThreadHelper.ThreadStart(System.Object)

[shiftkey]

Fixed in #436