Make nova-manage db archive_deleted_rows more explicit

* max_rows must be positive
    Provide a better error message of 'nova-manage db archive_deleted_rows
    --max_rows=' is negative.
* Requires a max_rows
* No hidden default of 5000

Fix bug 1145609
Fix bug 1151064

Change-Id: I9078ff2700a0329ac4aff68bb434be5f16a5a3f1
Merge "Make nova-manage db archive_deleted_rows more explicit"