TEST: Move transform test data, add test for coef->disp field conversion

tests/test_transform/test_affine.py

tests/test_transform/test_flirt.py

tests/test_transform/test_nonlinear.py

...est_transform/testdata/test_transform_test_axisBounds.txt

...s/test_transform/testdata/test_transform_test_compose.txt

tests/test_transform/testdata/test_transform_test_concat.txt

...sform/testdata/test_transform_test_flirtMatrixToSform.txt

tests/test_transform/testdata/test_transform_test_invert.txt

...ansform/testdata/test_transform_test_scaleoffsetxform.txt

...t_transform/testdata/test_transform_test_transform_00.txt

...t_transform/testdata/test_transform_test_transform_01.txt

...t_transform/testdata/test_transform_test_transform_02.txt

...t_transform/testdata/test_transform_test_transform_03.txt

...t_transform/testdata/test_transform_test_transform_04.txt

...t_transform/testdata/test_transform_test_transform_05.txt

...t_transform/testdata/test_transform_test_transform_06.txt

...t_transform/testdata/test_transform_test_transform_07.txt

...t_transform/testdata/test_transform_test_transform_08.txt

...t_transform/testdata/test_transform_test_transform_09.txt

...t_transform/testdata/test_transform_test_transform_10.txt