Updated skybox tutorial

[Aaron]

Hi All,

The latest dev build of L3DT includes an update to the Sapphire rendering plugin, which now supports skybox rendering. For those interested in customising the skyboxes, I've updated the skybox tutorial to include the new filenames required for Sapphire skyboxes, which are different to those used in L3DTVi2 (tutorial PDF here). Please note that the skybox rendering in Sapphire is a bit blocky in the current release, but this will be fixed in the next one.

Cheers,
Aaron.