Adding helper class for suppression of error message floods caused by error messages...

Adding helper class for suppression of error message floods caused by error messages occurring rather frequently, e.g. for every event.
The class suppresses the printout after an adjustable number of occurences and prints an error summary when the instance gets out of scope.
Simple usage by predefined macro
 * if (nastyerror) {
 *   ALIHLTERRORGUARD(5, "nasty error, first occurence in event %d", event);
 * }