Removing uploaded files when createFile/updateFileBody fails.
Cleaning job that periodically removes old files from the temp directories
Merged master & enabled cleanup for previews
Cleaner interval is now expressed in seconds.
Expanded some log statements with more information.
Added the cleanCallback to the ContentAPI.setPreviewItems method + cleaned up cleaner.
Merge pull request #365 from simong/filescleanup

Removing files when upload files + Clean job