Establish/document DataLad workflow for updating datasets on rolando with curation changes

[yarikoptic]

HeudiConv/ReproIn organized BIDS datasets are not curated. Labs ideally should fetch them using DataLad as described in instructions and curate and enhance them. As long as DataLad (or git/git-annex directly) are used, we can establish a nice and unambigous workflow to propagate those changes back to rolando's centralized collection of datasets. Curation entails

• removal or renaming of __dups with potential changes to IntendedFor of fmaps .json files (under git) if populated, and changes to _scans.tsv files (under annex).
• addressing TODOs as documented through out the dataset
• populate _events.tsv files

To make it work we need to

• establish git-annex storage per each dataset git-repo available to both DBIC personnel curating BIDS datasets (well, me ATM), and researchers. We could
  - use github for that with private repos, while automatically creating and populating repositories here. LFS for storing those _scans.tsv annexed files. That would also give us issues tracker etc. But even though private, not certain if "kosher". Also mapping rolando users to github might show to be pain
  - "mirror" entire hierarchy on rolando where we give write access to researchers to push changes. E.g. could be /inbox/BIDS-curated or alike (e.g. just a nearby bare git-annex repo with needed permissions for each dataset with -curated suffix in the name. The simplest way ATM and could be done on 'case by case' basis). Cons: no issue tracker. Pros: simple/easy
  - have gitlab DBIC instance provided somewhere internally. Pros: very featurefull, supports hierarchical organization, Cons: no git-annex support so we would still need the "mirror"
  - have gin (https://gin.g-node.org/) DBIC instance. Pros: has all needed features of github and supports git-annex .

@andycon WDYT about gitlab or gin instance for DBIC? In both gitlab and gin cases not sure on how easy to integrate with user accounts/permissions already out there. Needs "research"