Bug
[SDESK-6662](https://sofab.atlassian.net/browse/SDESK-6662) PNG image upload fails \(EWTN\)
[SDESK-6675](https://sofab.atlassian.net/browse/SDESK-6675) Unable to unlock article \(EWTN\)
[SDESK-6707](https://sofab.atlassian.net/browse/SDESK-6707) fix empty description in ninjs when abstract is present
[Changes](https://github.com/superdesk/superdesk-core/milestone/130?closed=1)