Delete harvested images when document is deleted

[karenmajewicz]

When a document is deleted from Solr, the associated image thumbnail should be flushed as well.

Real life example:

• A batch of records was uploaded with a mistake in the metadata where an unrelated Image Server address was inserted along with the correct Feature Server address.
• Our system harvested an image from the Image Server that does not match the record.
• I exported the metadata, deleted the Image Server link.
• I deleted the documents in GEOMG and re-uploaded the replacements. (note: the IDs were the same)

Odd behavior:

• In geodev.btaa.org, this worked. The thumbnails disappeared.
• In geo.btaa.org, this did not work. The thumbnails persist. (look for the ones with aerial imagery just along the middle of the state)

[karenmajewicz]

Need to find different examples as I deleted the ones that I originally was working with for this issue.