Decided it's too scary to make v6 unlocked files have 1 copy by default,
but that should be available to those who need it. This is consistent with
git-annex not dropping unused content without --force, etc.
* Added annex.thin setting, which makes unlocked files in v6 repositories
be hard linked to their content, instead of a copy. This saves disk
space but means any modification of an unlocked file will lose the local
(and possibly only) copy of the old version.
* Enable annex.thin by default on upgrade from direct mode to v6, since
direct mode made the same tradeoff.
* fix: Adjusts unlocked files as configured by annex.thin.
i found that most man pages only had references to the main git-annex
manpage, which i stillfind pretty huge and hard to navigate through.
i tried to sift through all the man pages and add cross-references
between relevant pages. my general rule of thumb is that links should
be both ways unless one of the pages is a more general page that would
become ridiculously huge if all backlinks would be added
(git-annex-preferred-content comes to mind).
i have also make the links one per line as this is how it was done in
the metadata pages so far.
i did everything but the plumbing, utility and test commands, although
some of those are linked from the other commands so cross-links were
added there as well.
