rem: void KMFilterActionIdentity::clearParamWidget( QWidget * paramWidget ) const
add: void KMFilterActionAddHeader::clearParamWidget( QWidget* paramWidget ) const
context: void KMFilterActionIdentity::clearParamWidget( QWidget * paramWidget ) const{  IdentityCombo * ic = dynamic_cast<IdentityCombo*>( paramWidget );  assert( ic );  ic->setCurrentItem( 0 );  //ic->setCurrentIdentity( kmkernel->identityManager()->defaultIdentity() );}