rem: MimeTypeEditor::UpdateText()
add: NumberEditor::UpdateText()
context: MimeTypeEditor::UpdateText(){	if (fEditor.Lock()) {		const char *mimeType;		if (fEditor.GetViewBuffer((const uint8 **)&mimeType) == B_OK) {			fTextControl->SetText(mimeType);			fPreviousText.SetTo(mimeType);		}		fEditor.Unlock();	}}