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_ext_viewcode.py

@@ -1,43 +1,32 @@
-# -*- coding: utf-8 -*-
-"""
-    test_ext_viewcode
-    ~~~~~~~~~~~~~~~~~
-
-    Test sphinx.ext.viewcode extension.
-
-    :copyright: Copyright 2007-2014 by the Sphinx team, see AUTHORS.
-    :license: BSD, see LICENSE for details.
-"""
-
-import re
-
-from six import StringIO
-
-from util import test_roots, with_app
-
-
-warnfile = StringIO()
-root = test_roots / 'test-ext-viewcode'
-doctreedir = root / '_build' / 'doctree'
-
-
-def teardown_module():
-    (root / '_build').rmtree(True)
-
-
-@with_app(srcdir=root, warning=warnfile)
-def test_simple(app):
-    app.builder.build_all()
-
-    warnings = re.sub(r'\\+', '/', warnfile.getvalue())
-    assert re.findall(
-        r"index.rst:\d+: WARNING: Object named 'func1' not found in include " +
-        r"file .*/spam/__init__.py'",
-        warnings
-    )
-
-    result = (app.outdir / 'index.html').text(encoding='utf-8')
-    assert result.count('href="_modules/spam/mod1.html#func1"') == 2
-    assert result.count('href="_modules/spam/mod2.html#func2"') == 2
-    assert result.count('href="_modules/spam/mod1.html#Class1"') == 2
-    assert result.count('href="_modules/spam/mod2.html#Class2"') == 2
+# -*- coding: utf-8 -*-
+"""
+    test_ext_viewcode
+    ~~~~~~~~~~~~~~~~~
+
+    Test sphinx.ext.viewcode extension.
+
+    :copyright: Copyright 2007-2014 by the Sphinx team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+
+import re
+
+from util import with_app
+
+
+@with_app(testroot='ext-viewcode')
+def test_simple(app, status, warning):
+    app.builder.build_all()
+
+    warnings = re.sub(r'\\+', '/', warning.getvalue())
+    assert re.findall(
+        r"index.rst:\d+: WARNING: Object named 'func1' not found in include " +
+        r"file .*/spam/__init__.py'",
+        warnings
+    )
+
+    result = (app.outdir / 'index.html').text(encoding='utf-8')
+    assert result.count('href="_modules/spam/mod1.html#func1"') == 2
+    assert result.count('href="_modules/spam/mod2.html#func2"') == 2
+    assert result.count('href="_modules/spam/mod1.html#Class1"') == 2
+    assert result.count('href="_modules/spam/mod2.html#Class2"') == 2