Profile feature wanted for backing up function

[cuilongbo]

Profile feature is only supported for upgrading in version 2.2.3. It might be more useful for backing up function, since backing up is a usual task for administrators and is usually configured as a cron task.

Although it works if setting a file as the input, such as:

redmine backup ~/redmine2/ < my_input.txt

It is better to support profile feature, like:

redmine backup ~/redmine2/ --profile 1