SD-324 : Upload images to the Content Archive
fix(upload): save only changes in upload event handler
fix(logger): set sys.stderr logger when in debug mode
feat(archive): add archive_ingest api
SD-324 : Upload images to the Content Archive
fix(upload): return media id as part of data uri not upload id
Improve upload performance by disabling file inclusion in the response.
test(archive): add test for upload to archive

close #58
fix(data): remove elastic put_mapping call from datalayer

it gets called from elastic init_app
SD-324 : Upload images to the Content Archive

Conflicts:
	superdesk/items.py
SD-315 : _created and _updated fields display invalid date