Pull request batch1: Big batch of simple pullrequests that are ready to merge in my opinion

Following pull requests are grouped in this PR:
https://github.com/s3tools/s3cmd/pull/369
https://github.com/s3tools/s3cmd/pull/348
https://github.com/s3tools/s3cmd/pull/355  ( Bugfix import error)
https://github.com/s3tools/s3cmd/pull/385