Testing Times, Part 2

As a result of not fully understanding the nature of the t:document element in the XProc Test Suite tests I've done a few changes that now treat results containing document-node sequences as sequences of document nodes rather than one document with more than one document element. This is all well and good, but more interesting will be if I can implement an eval step that can take an XProc pipeline as an input, compile it and apply it to the source input. The next step would be to re-cast all the Test Suite tests as XProc pipelines (I haven't checked them all to see if that's possible) and then I think that would be a much better solution for the test suite.