dropunused behavior change: Now refuses to drop the last copy of a file, unless you use the --force.

This was the last place in git-annex that could remove data referred to by
the git history, without being forced.

Like drop, dropunused checks remotes, and honors the global annex.numcopies
setting. (However, .gitattributes settings cannot apply to unused files.)
unused: No longer shows as unused tmp files that are actively being transferred.
correct changelog; git annex get --unused doesn't make sense
Added a comment
update
Added a comment
Added a comment: ~/annex/.git/config files (after running the steps above)
Added a comment
Added a comment
Merge branch 'master' of ssh://git-annex.branchable.com
Added a comment
removed
Added a comment
Added a comment
Added a comment
Added a comment
Added a comment
Added a comment