Using the extract(1) program to do the heavy lifting.
Decided to make git-annex run pre-commit-annex when committing. Since
git-annex pre-commit also runs it, it'll be run when git commit is run too,
via the pre-commit hook. This basically gives back the pre-commit hook
that git-annex took away. The implementation avoids repeatedly looking
for the hook script when the assistant is running and committing
repeatedly; only checks if the hook is available once.
To make the script simpler, made git-annex metadata -s field?=value
only set a field when it's not already got a value.
This commit was sponsored by bak.
