Move file system tests

Brad had suggested the contents of test/io/fsouza and most of test/io/lydia
would more accurately be filed under test/modules/standard/FileSystem, since
they live in a separate module now.

This is multiple commits because the git diff looked so large I figured I
would accidentally add a file I didn't want to add if I committed it all in a
single commit.  Good thing that's what merges are for!

Note: I left octalPrint and otherIntConfig in test/io/lydia, since they are
more related to print formatting than to the file system functionality that
motivated them.