s3cmd get to stdout: set file_exists to avoid traceback, bug #175

Fixes https://github.com/s3tools/s3cmd/issues/175
Reported by Seth Noble.

Set file_exists so we don't try to delete sys.stdout if getting the
file happens to fail.
Fixed typos in CloudFront error messages.
Merge pull request #176 from mdomsch/bug/175

s3cmd get to stdout: set file_exists to avoid traceback, bug #175
Minor whitespace fixups
Merge branch 'master' of ssh://github.com/s3tools/s3cmd
Don't require 'json' - disable IAM when not available
Typo in manual
Merge pull request #183 from EtienneM/master

Update man --ws-index/--ws-error