tests: Big push to get the tests to pass again. - Lots of fixes everywhere in the code. - Try to handle debug logging in the multiprocessing worker pool when running in pytest. Not perfect, but usable for now. - Replace all `.md` test files with `.html` since now a auto-format extension always sets the format. - Replace `out` with `outfiles` in most places since now blog archives are added to the bake output and I don't want to add expected outputs for blog archives everywhere.

--- a/piecrust/data/paginator.py	Sun Oct 29 22:46:41 2017 -0700
+++ b/piecrust/data/paginator.py	Sun Oct 29 22:51:57 2017 -0700
@@ -208,6 +208,7 @@
         self._iterator.slice(offset, limit)
 
         self._iterator._lockIterator()
+        self._iterator._load()
 
         if isinstance(self._source, ContentSource):
             self._onIteration(self._iterator)