Node context for filters

I know this has been talked about before with mixed results, but here is a patch that passes node context to filters. I ran into the need to do this when I was converting the glossary module to use nodes instead of taxonomies. The glossary filter is an expensive filter so it needs to be included in the filter cache. In addition I want control of the filter settings per filter format type. It is very silly to recreate the admin screens infrastructure as well as hack the filter into a nodeapi where it only filters nodes. This filter just needs to make sure it is not filtering a node for itself (not linking back to itself because it uses a synonym or the term in it's description).