init: Fix a reversion in the last release that prevented automatically
generating and setting a description for the repository.
Seemed best to factor out uuidDescMapRaw that does not
have the default mempty descrition behavior.
I don't much like that behavior, but I know things depend on it.
One thing in particular is `git annex info` which lists the uuids and
descriptions; if the current repo has been initialized in some way that
means it does not have a description, it would not show up w/o that.
(Not only repos created due to this bug might lack that. For example a repo
that was marked dead and had --drop-dead delete its git-annex branch info,
and then came back from the dead would similarly not be in the uuid.log.
Also there have been other versions of git-annex that didn't set a default
description; for years there was no default description.)
When downloading an url and the destination file exists but is empty,
avoid using http range to resume, since a range "bytes=0-" is an unusual
edge case that it's best to avoid relying on working.
This is known to fix a case where importfeed downloaded a partial feed from
such a server. Since importfeed uses withTmpFile, the destination always exists
empty, so it would particularly tickle such problem servers. Resuming from 0
is otherwise possible, but unlikely.
Avoid a delay at startup when concurrency is enabled and there are
rsync or gcrypt special remotes, which was caused by git-annex
opening a ssh connection to the remote too early.
sshOptions makes a connection to the ssh server if one is not already open,
when concurrency is enabled. Avoid doing that at startup, when the remote
list is being built, but the remote may not be used at all.
Instead, rsync/gcrypt now runs sshOptions once per ssh connection to the
server. This should not be significant overhead since Remote.Git already
has the same overhead (as do Bup and Ddar).
Add back support for ftp urls, which was disabled as part of the fix for
security hole CVE-2018-10857 (except for configurations which enabled curl
and bypassed public IP address restrictions). Now it will work if allowed
by annex.security.allowed-ip-addresses.
When a remote is configured to be readonly, don't allow changing what's
exported to it.
This was missed in the original export remote implementation, but it makes
sense for a readonly export remote to not be allowed to change.
