New API methods

• listIncompleteUploads similar to listObjects but for partially uploaded multipart uploads.
• removeIncompleteUpload - renamed from dropIncompleteUpload
• presignedPutObject
• presignedPostPolicy
• remove 'milkyway' as default region - default to 'us-east-1'

New API preSignedGetObject() and improved examples

0.2.5

Bump to 0.2.5

Examples simplified and provide new shadowJarred artifact

0.2.4

Bump to 0.2.4

Major refactor release

0.2.3

Bump to new release 0.2.3

Moved from google-http to squareup/okhttp

This release also deprecates support for OpenJDK6, OracleJDK6 since they are not supported anymore with no futher security fixes coming in.