Redefine torus object texcoords

Redefine torus standard object texcoords so that the [0, 1]
range maps exactly to circumferences of the two circles that
define the torus.

Signed-off-by: Harm Hanemaaijer <fgenfb@yahoo.com>
Improve texture creation flags, add flag for wrap-repeat

Improve texture creation by adding a wrap-repeat flag
(instead of a fixed type) and add an uncompressed flag.

Add a 64x64 normal map in PNG, ETC1 and RGTC2 formats. Add mipmaps
to the 256x256 ETC1 normal map.

Update demo5 to use a repeating 64x64 normal map for the torus
objects, making use of a UV transform, improving performance and
consistency.

Signed-off-by: Harm Hanemaaijer <fgenfb@yahoo.com>