texture clamping flag

[alex25]

just started updating the tracks to use both the shadow flag and the texture clamping one. worked fine for estoril88 (those ugly edges are gone now for the backgrounds. thanks joe). unfortunately it didn't seem to work for hockenheim as the background texture is completely mangled. i wonder if it's my video driver (nvidia 180.41 on linux) of if there is something about this texture that's mishandled by the new code. the new list.txt is in svn so just update and see of it works for you.

--alex--