Navigation
* added 'particletext' var for toggling particle text
* alias arguments now set by 'push' on execution, and restored by 'pop' after
* added 'push' and 'pop' commands for saving and restoring aliases
* glass reflection using environment maps
* added environment map entities (created by "newent envmap") for reflecting geometry
* added S3 texture compression support (controlled by "mintexcompresssize" var)
* added Gregor's new texture set and map, and many other new maps/media
* added heightmaps for most existing normalmapped textures, so we can have parallax on everything
* added scripting documentation for the rpg
