Allow overriding previous uploads

[nemobis]

As requested by phe: at least admins will need an option to delete all files, reupload images and overwrite all metadata for older uploads. The early imports from Google Books have partial metadata coverage and are sometimes very hard to read due to low resolution.

[phil-el]

If there is a db tracking upload, you could restart uploading of all items previous a given timestamp but can the bot upload over existing items ? (delete all then upload again). And yes allowing an uploader to manually reupload will be handy too..

[jjjake]

The default behavior of item.upload() in the internetarchive lib is to clobber a file if it already exists, so @phil-el, yes, the bot should be able to upload over existing items without too much trouble. Though, I'm not very familiar with the BUB code base.

[LeadSongDog]

How is this not contrary to the fundamental purpose of an archive? Existing items should not be "clobbered", just given some sort of lower relevance among query results. Add annotations to the old items for this effect, sure, but never delete them.

[nemobis]

This is not about items but files. Lower quality copies of the identical same images, or broken tar files, don't need to be preserved.