lowercased Institute.
Updated title, description and comments for base characterization object.
Updated title, description and comments of files and file relationships. Additionally added identifying properties to files to be used as references in programatic submission.
Changed free-text to plain text.
Updated title, description and comments of datasets and experiments. Additionally added identifying properties to files to be used as references in programatic submission.
Fixed the accident replacment OBSOLETE with DELETED.
Updated pattern of encode_dbxref so that the tests now pass and match the appropriate encode2 experiment ids.