Complete test suite overhaul.

* rename a few test modules to make the names more consistent

* do not copy/use Sphinx from build/ (unnecessary without 2to3)

* use a temporary dir for *all* test projects, the source tree
  will stay pristine that way  (default is tests/build)

* speed up tests by ~3x by splitting up test projects and avoiding
  rebuilds

tests/test_setup_command.py

@@ -16,11 +16,16 @@ from functools import wraps
 import tempfile
 import sphinx
 
-from util import with_tempdir, test_roots, SkipTest
+from util import rootdir, tempdir, SkipTest
 from path import path
 from textwrap import dedent
 
-root = test_roots / 'test-setup'
+root = tempdir / 'test-setup'
+
+
+def setup_module():
+    if not root.exists():
+        (rootdir / 'roots' / 'test-setup').copytree(root)
 
 
 def with_setup_command(root, *args, **kwds):