Create a Node map to get proper node translations
In a multi-language setup, before this commit the Node's Translations() method
would return some "dummy nodes" that would point to the correct page (Permalink),
but would not be the same as the node it points to -- it would not have the translated
title etc.
The node creation is, however, so mingled with rendering, whihc is too early to have any global state,
so the nodes has to be split in a prepare and a render phase. This commits does that with as small
a change as possible. This implementation is a temp solution until we fix #2297.
Updates #2309