Merge duplicate scraper code

[xloem]

The files in scrapers/ contain almost the same code.

This means if features are added to one (like adding seller information) they aren't added to the other.

It would be good to pull similar code out of them and reuse it by reference, or pull out and parameterize the differences between them.

[cpatrickalves]

The files with _au_ in the name are for eBay of Australia. The two files for Australia could be merged, I'll do this in the future.

Unfortunately, I don't have time to update this code now.

Thanks anyway.