Projected image does not convert

[Tim-Evans-Seequent]

plane_surface.omf.gz fails to convert from OMF1 with these errors:

• 'Orient2::u' must be a unit vector but [0.0026686676037428235, 0.0003693918434559309, 0.0] length is 0.0026941, inside 'test'
• 'Orient2::v' must be a unit vector but [-0.0002940052925535278, 0.003057655042556713, 0.0] length is 0.0030717, inside 'test'
• 'Orient2' vectors are not orthogonal: [0.0026686676037428235, 0.0003693918434559309, 0.0] [-0.0002940052925535278, 0.003057655042556713, 0.0], inside 'test'

The file is exported from Leapfrog. There are two issues here:

1. The U and V vectors are very short, likely the size of one pixel, and will need to be normalised.
2. The U and V vectors aren't orthogonal, and probably shouldn't be required to be.

Change the code here to allow skewed images, and to correctly normalise the U and V vectors when converting OMF1 images.