message: added removeError method for the question
diff: @@ -987,6 +987,15 @@ export class Question extends SurveyElement
  public addError(error: SurveyError) {
  this.errors.push(error);
  }
  + /**
  + * Remove a particular error from the question error list.
  + * @param error
  + */
  + public removeError (error: SurveyError) {
  + var errors = this.errors;
  + var index = errors.indexOf(error);
  + if (index !== -1) errors.splice(index, 1);
  + }
  private checkForErrors(): Array<SurveyError> {
  var qErrors = new Array<SurveyError>();
  if (this.isVisible && !this.isReadOnly) {
  