Allow fetching AccessToken through the flow.

Fixed offset float value error.
Allow Downloading large files directly to the specified location

Allow autorename for createFolder. Closes kunalvarma05#25.

Fixes the revokeAccessToken bug kunalvarma05#21.

Fix PersistentDataInterface -> PersistentDataStoreInterface typo

Decode JSON only is response is JSON. Fixes kunalvarma05#13

Fixes Chunked Upload Bug

Fix saveCopyReference and restore return types