simplefeed 5.x-2.0

- #193977 - fix views namespace conflicts with FeedAPI
- check_url() before sending to token module
- simplify feed refreshing, using $nid instead of $vid, and improving performance slightly
- #218084 - fix cache to work with both public and private file systems
- much more efficient routine for processing feeds
- add a feed hash to determine when a feed has been updated, improves performance significantly
- improve unique feed item id to simply be a hash of title & body, which is more robust and much
faster to compute, removing costly serialize()
- #136395 - improve taxonomy support, making it faster and supporting regular taxonomies along with
free tagging