Update file.py

File size to DCC ACTION
missing paired with to DCC ACTION
platform to ENCODE3 only
Update experiment.py

missing replicate aired end to error
missing library paired end to warning
Update file.py
Update item.py

upgrade failure go to DCC action
Specifying the object in the detail
Update file.py
Merge pull request #549 from ENCODE-DCC/1851-level_changes

1851 level changes