* error handling - GConf has two ways of handling errors: the first, catch
  every error, the second leave the unhandled errors up to the programmer;
  unhandled errors are triggered by not passing a GError to the C functions
  and listening to the "unreturned_error" signal; right now, we're using the
  default error handler set inside GConf, leaving to the programmer the
  ability to catch every error that occurs via the "error" signal.