Revert "Removed unnecessary files"

This reverts commit a904d4a8a05d47dfa47547d99be7de4f563e7293.
Added FPS measuring means

Added fps.wrl and index-fps.wrl.

fps.wrl downloaded from:
http://dcgi.felk.cvut.cz/home/zara/PGR012/fps.wrl
index-fps.wrl simply inlines index.wrl and fps.wrl. It displays the
scene and prints FPS into console.

On my computer in Cortona 3D, it's necessary to hide the console after
the simulation starts in order to display the FPS values.
Lighthouse body: Prototyped, added LOD

Made the lighthouse body a prototype. Added a togglable LOD feature with
3 levels of detail: original extrusion, plain cylinder and empty node.
Several improvements