NLog/NLog — pull request #359 by cvanbergen (2014-06-10 06:27:48+00:00)
Title: Fix #71 : Removing invalid filename characters from created file

Adding a CleanUpFileName method to replace characters that are invalid
according to System.IO.Path.GetInvalidFileNameChars()
Changed an existing UnitTest that relied on an exception that would be
thrown when an invalid filename was used.
This will resolve issue #71.