Add arg for path to FreeSurfer license.

FreeSurfer license now works the same as in abcd-bids-pipeline: there is a default (FreeSurfer path), but user can override with an argument.
Also, Dockerfile was updated to get the latest pipeline code in which there were fixes to the path taken when a user supplies a T1w mask to be used in PreFreeSurfer.

smoothing, fmaps, threads

This release has 3 main changes:

• New --smoothing-iterations option allows user to choose the number of iterations to pass to FreeSurfer.
• Infants pipeline now uses the "IntendedFor" field in fmaps. Note: previously all fmaps were used for all func files. Now, if no "IntendedFor" field, the fmap is not used.
• We now cap the thread-pool, when processing tasks, at 6. There were memory problems when we tried to process too many at once, no matter how much memory we threw at it. So this "fix" allows us to still use 10 cores (needed to get through PreFreeSurfer in a reasonable amount of time), but not restart to use fewer cores for the functional processing.

Initial public release

Initial public release of the infant pipeline.