hopefully fixes #3350.  We need to test dropping old assets using different dates (with content that would be dropped at one date and not the other and using really large datasets.
another fix for #3350
another fix for #3350 - allow drop iteration to be done by seconds
another fix for #3350
another fix for #3350
Merge pull request #3354 from dotCMS/issue-3350-drop-old-assets-does-not-complete

Issue 3350 drop old assets does not complete