The clamped_texture function (4 pairs of texture coordinates), was using tt instead of tt2 in the 1st pair. This is fixed to tt2 as it should be, for both float and color clamped_texture. There was a problem in the "box" projection when getting filterwidth of ST coordinates - filterwidth uses Du() and Dv(), and was being called inside varying conditionals. This was fixed, the filterwidth(ss) and (tt) statements are moved outside the varying conditional. Minor cleanups in texture functions.
