test for using logger default errorhandler with streamwriter
[#5383] Remove error handling calls

- The error handling calls pop the scope when already inside an error handler --
  such as when you use the Logger as an error handler. The only call inside the
  block that could be a potential problem is the one to format a DateTime object
  -- and then, only if the format is invalid (in which case you have bigger
  problems).
[#5383] Remove unused use statement
[#5383] Use error suppression *gulp*

- The only viable solution that (a) prevents recursion during serialization, and
  (b) allows the Logger to work as an error handler after a message has been
  formatted, is to use the error suppression operator. See the comment in the
  normalize method for details.
Merge pull request #5383