Scene rendering logic is now better

Box objects (AABB) now have the long awaited extent() and center()
methods. Corners are now called “aa” and “bb” for convenience. The
WorldEntity class uses a box3 for its AABB instead of two vec3s.
This allows us to simplify a lot of verbose code.

and 2) fuck the Visual Studio compiler that crashes when confused.

scene so that g_scene can be deprecated later.

Added RemoveElement

- removed 0 CR characters
 - removed 0 trailing whitespaces
 - replaced 5 tabs with spaces
 - fixed 1 svn:eol-style properties

on automake platforms, too.

directory layout mess.

issues that were introduced with the Direct3D changes.

cannot used DirectX 10 because my video card only supports DX9, and there
is no compatibility layer. DX11 has feature levels for older hardware so
it would work with a DX9 card, but it's not available for WinXP.

that are not explicitly real, even with namespace mistakes.