Core: Add compile time option to use native OS logging facility

* This change makes it easier to debug issues in UI applications
  which don't necessarily have a console connected to stderr.
* Outputting to the debugger shouldn't occur in normal situations so
  this change has to be explicitly enabled by a build-time config flag.
* Uses OutputDebugString() on Windows platforms or the syslog facility
  on other OSes, if available.
* Also align the report of configure defaults to autotool's.