Create README.md
Update README.md

Better README for quick lookups
Merge pull request #17 from kirang89/master

Better README for quick lookups
Let bucket name be empty

This will let users work with the service instead of buckets and objects. It should be noted that a lot of operations simply do not work as they should. For example S3Bucket.listdir only works for buckets as the XML is very specific.
Fix listdir bug from previous commit