- Offloads uploading to GitLab Workhorse
- Use /authorize request for fast uploading
- Added backup recipes for artifacts
- Support download acceleration using X-Sendfile

Documentation elsewhere refers to this internal path, let's keep
it.

By using light gzip compression we can save a lot of disk IO during
the backup.

During the backup we create an intermediate copy of two directories:
builds and uploads. Instead of creating many small files with 'cp
-r', we now use tar (and fast gzip) to create single intermediate
files. This saves on disk IO and disk space while creating a backup.

This adds support for AWS S3 SSE with S3 managed keys, this means the
data is encrypted at rest and the encryption is handled transparently to
the end user as well as in the AWS Console. This is optional and not
required to make S3 uploads work.

This sidesteps problems with running 'chmod' on some CIFS mounts.

This change helps system administrators who want to replicate
GitLab backup files without needing root permissions.

When creating backup tar files, only change permissions on the `db`,
`uploads`, and `repositories` directories, not their contents.

Use more restrictive permissions for backup tar files and for the db,
uploads, and repositories directories inside the tar files.

This reverts commit c42262b4, reversing
changes made to c6586b12.

Use more restrictive permissions for backup tar files and for the db,
uploads, and repositories directories inside the tar files.

This reverts commit 7d5f86f6.

This commit moves the note folder from
/public/uploads/note
to
/uploads/note
and changes the uploader accordingly.
Now it's no longer possible to avoid the access control by modifing the url.
The Avatar upload has been refactored to use an own uploader as well
to cleanly seperate the two upload types.

This change also shows the output of failed Git commands during the
backup.

Fixes a bug with non-UTF8 locales introduced by
2b816075.

Previous to this commit, backups were tied to the git revision (SHA1) of
the app at the time the backup:create command was invoked. If the SHA1
at the time of restore was different, the script would refuse to restore
the backup.  This commit loosens this tie so that the backup script only
complains if the value of the Gitlab::VERSION constant is different
between the time of backup and the time of restore.

These fixes will allow a restore of gitlab when the backups and
repositories directories are in non-standard locations (ie sub-dirs
of gitlabhq).  Also allows the restore to be run from script
overriding the need of a user to confirm the rebuild of the
authorized_keys file.

If the backup directory is not sub the gitlab install directory,
then the git rev-parse call will fail.