Bug: Detach Tabs loses history

[Daniel Teske]

Hi

Detached Tabs lose their history, this patch fixes that.

mainWindow->childFrame()->frameType() should always be of type "Tabs",
because
  if ( m_pDocContainer->frameType() != "Tabs")
    convertDocContainer();

because currentFrame is of type tabs, which is written to the config,
and loadItem restores it.

QString prefix = QString::fromLatin1( currentFrame->frameType() ) +
QString::number(0);
config.writeEntry( "RootItem", prefix );