Create the ability to filter based on multiple maps

[jdrich]

Consider the following:

Tag associations
Search terms
Categories
Archives

Need to be able to say "This page is rendering with a post in this category," etc.

[jdrich]

The idea here was to have a Filter that can combine the output of two maps. That filter would do some sort of intersect on the maps to create the page object.

For example, to associate a post with its tag cloud and category, you might feed those three maps into a filter and then associate them all based on the category name. The output would be another map which would contain the post with its associated category and tag data.