gordon's sandbox: Feeds Delete

Feeds is good at handling "river of news" style feeds, but feeds such as product feeds are very much lacking. In the case of a product feed, unlike a "river of news" which will have x number of items in, it will have all the products in the feed. Feeds will allow you to purge items x number of days after it has been loaded onto the system, but in the case of product feeds we want all products to remain until an item has been removed from a feed.

Feeds delete will track all items in a feed and mark them every time an item is seen, so that we can then based upon configuration, delete the item from the system.

This module requires a lot of changes to Feeds in order to work. These following patched which are included in the patches directory have been submitted for inclusion in Feeds.

#1961998: Add new hook hook_feeds_before_update()
#1362378: Provide entity post-save hook
#1962006: Add hook hook_feeds_config_defaults() to allow other modules to add extra configuration
#1962014: Expose FeedsProcessor::entityDeleteMultiple() as a public method