VID-1568 Update image & video_info tables in single transaction
The logic of updating video_info was taken out of the hook; also cache logic was separated from datastore update
VID-1568 Cleaner conditional per @garthwebb
VID-1568 Remove hook VideoInfoHooksHelper::onFileUpload
/CC @jsutterfield @garthwebb
Merge pull request #3888 from Wikia/VID-1568

VID-1568 - update image and video_info in a single transaction