WIP: Don't do COM initialization for "syn-only" reg

[cookpa]

No description provided.

[cookpa]

@stnava @ntustison I have got this doing a default Identity initial transform for the "syn only" transforms:

    deformable_only_transforms = ["SyNOnly", "antsRegistrationSyN[so]", "antsRegistrationSyNQuick[so]",
                                  "antsRegistrationSyNRepro[so]", "antsRegistrationSyNQuickRepro[so]",
                                  "antsRegistrationSyN[bo]", "antsRegistrationSyNQuick[bo]",
                                  "antsRegistrationSyNRepro[bo]", "antsRegistrationSyNQuickRepro[bo]"]

I'm going to add the TV* as well

[cookpa]

Actually, question: the initial transform

          # '-r', initx,

is simply commented out for the TV methods, so you actually can't pass an initial transform. Is it OK if I let people specify an initial transform with default of Identity?

[ntustison]

Yeah, that sounds reasonable to me.

[coveralls]

coverage: 79.673% (+0.01%) from 79.662%
when pulling d1590d5 on syn_only_init
into 80826f5 on master.