Hide elements of the HUD (health/magicka/stamina bars,
minimap) when the corresponding windows (stats/map) are pinned.
Rearrange the remaining hud elements in such cases (like in the
original Morrowind).
Separate MapWindow from bunch of classes in layouts.cpp/hpp
Inherit it from WindowPinnableBase.
TODO: map arrow (player position) updates orientation only
when you open the inventory. When the map window is pinned,
the arrow direction is not updated.