Load conftest files in the correct order initially

When the conftest.py files are looked for intially they got loaded
starting from the subdir ending at the parent dir(s).  Later on during
collection any conftest.py files are loaded starting from the parent
dir ending at the subdir.  Due to how extending fixtures works the
latter is correct as otherwise the wrong fixture will be available.
So this changes the initial conftest loading to start at the root and
go towards the subdir.

This does also affect the order of other hooks, hence the order of the
reporting being different in testing/test_terminal.py.

testing/python/fixture.py

@@ -102,6 +102,77 @@ class TestFillFixtures:
             "*2 passed*"
         ])
 
+    def test_extend_fixture_module_class(self, testdir):
+        testfile = testdir.makepyfile("""
+            import pytest
+
+            @pytest.fixture
+            def spam():
+                return 'spam'
+
+            class TestSpam:
+
+                 @pytest.fixture
+                 def spam(self, spam):
+                     return spam * 2
+
+                 def test_spam(self, spam):
+                     assert spam == 'spamspam'
+        """)
+        result = testdir.runpytest()
+        result.stdout.fnmatch_lines(["*1 passed*"])
+        result = testdir.runpytest(testfile)
+        result.stdout.fnmatch_lines(["*1 passed*"])
+
+    def test_extend_fixture_conftest_module(self, testdir):
+        testdir.makeconftest("""
+            import pytest
+
+            @pytest.fixture
+            def spam():
+                return 'spam'
+        """)
+        testfile = testdir.makepyfile("""
+            import pytest
+
+            @pytest.fixture
+            def spam(spam):
+                return spam * 2
+
+            def test_spam(spam):
+                assert spam == 'spamspam'
+        """)
+        result = testdir.runpytest()
+        result.stdout.fnmatch_lines(["*1 passed*"])
+        result = testdir.runpytest(testfile)
+        result.stdout.fnmatch_lines(["*1 passed*"])
+
+    def test_extend_fixture_conftest_conftest(self, testdir):
+        testdir.makeconftest("""
+            import pytest
+
+            @pytest.fixture
+            def spam():
+                return 'spam'
+        """)
+        pkg = testdir.mkpydir("pkg")
+        pkg.join("conftest.py").write(py.code.Source("""
+            import pytest
+
+            @pytest.fixture
+            def spam(spam):
+                return spam * 2
+        """))
+        testfile = pkg.join("test_spam.py")
+        testfile.write(py.code.Source("""
+            def test_spam(spam):
+                assert spam == "spamspam"
+        """))
+        result = testdir.runpytest()
+        result.stdout.fnmatch_lines(["*1 passed*"])
+        result = testdir.runpytest(testfile)
+        result.stdout.fnmatch_lines(["*1 passed*"])
+
     def test_funcarg_lookup_error(self, testdir):
         p = testdir.makepyfile("""
             def test_lookup_error(unknown):