DOC: Update documentation. Code is now broken

doc/fsl.scripts.rst

doc/images/fnirt_warp_field.png

doc/images/fnirt_warp_field.xcf

doc/images/x5_linear_transform_file.png

doc/images/x5_linear_transform_file.xcf

doc/images/x5_nonlinear_coefficient_field_file.png

doc/images/x5_nonlinear_coefficient_field_file.xcf

doc/images/x5_nonlinear_displacement_field_file.png

doc/images/x5_nonlinear_displacement_field_file.xcf

fsl/transform/flirt.py

fsl/transform/fnirt.py

fsl/transform/x5.py