implemented download method
implemented "createFolder" method
implemented "Delete" method
implemented move method
implemented copy method for dropbox and added methods headers to GoogleDrive and AmazonS3
implemented 'listData' method along with required sub functions.
implemented 'getLink', 'getMedia', 'getCopyReference' and 'getThumbnail'-functions
implemented search and delta functions, added NotYetImplementedException
added new lines at end of file
Merge pull request #5 from massiveart/feature/dropbox

Feature/dropbox