for 15 bit normals, added branches to quantize the vector (0,0,0) as 0, to unquantize 0 as (0,0,0), and to quantize no non-zero vector as 0.
for 15 bit normals, added branches to quantize the vector (0,0,0)
as 0, to unquantize 0 as (0,0,0), and to quantize no non-zero vector
as 0.


git-svn-id: 9e9401559e51101c165cdce4d49b411eb20436ed@74 3d70eeeb-363e-0410-a505-8a46323a89f2

BRAINSia/teem,Slicer/teem,Slicer/teem,Slicer/teem,Slicer/teem,BRAINSia/teem,BRAINSia/teem,BRAINSia/teem,BRAINSia/teem,Slicer/teem