Only calculate the MD5 from a file if it wasn't provided in the metadata
Merge branch 'master' of https://github.com/aws/aws-sdk-java into s3-putObject-md5-file

Conflicts:
	src/main/java/com/amazonaws/services/s3/AmazonS3Client.java
Merge pull request #225 from ankon/s3-putObject-md5-file

Only calculate the MD5 from a file if it wasn't provided in the metadata