expanded by the shell.

forwarded to parent process in addition to being captured and returned (#373)

fsl.utils.fslsub.submit)

propertk to check load state

created from a str or Path obj

packages to preserve compatibility with python 2. But py2-compat is no longer
a goal, so we can now use native namespace packages.

"T1w.json" is a valid sidecar file

metadata file name, as files within a BIDS data set may be sym-linked from
another file/directory structure (e.g. datalad/git-annex)