one instance, if two or more threads accessed a method at the same time.

state. Image.save ensures that file name has an extension. MGHImage uses both
of these changes so that its initial save state is accurate, and when it
is saved, it is saved as a nifti

request now uses exported PREFIX

See merge request fsl/fslpy!44

Modified to request install

See merge request fsl/fslpy!43

  - if moving a file from a group, need to remove the entire group
  - Special test for when dest is a non-existent directory

dirname. Make it abs

called() to get the function.