Simplified Iterator a bit
Making Iterator even simpler, but the way it works now, it never flushes its buffer because the algorithm always keeps one iterator alive
Made buffer simpler still. Now to make it flush when there's only one iterator left, or all are the same
Keeping it simple for now, don't care if it buffers for ever
Added a rewriter test
Added another test: Returns unchanged when we don't find the tags in the library
Added another test: Ignores attributes we don't care
vamp'd up tests.
Added a test for the config