I found that s3put and s3multiput have diverged a bit from each other, so i re-synced them with each other and ported the missing functionality between them.
These two tools should probably be merged into one with the option to choose if doing --multiput or not, but that's another pull-request.
updated due to 08e6393
s3put s3multiput: Cleanup and resync of the code.
Both of them have the same heritage, and it would be nice they where
kept in sync.
s3put: add --key_prefix to prefix keys in s3
s3put: remove erronus v in getopt
s3put: document --headers option
s3multiput: add --header to send custom headers
s3multiput: expand prefix path
This is the same as 08e6393, but for
s3put s3multiput: remove unused counter total
This is superseded by #1078