merge config, pluginmanager, main into one file

--HG--
branch : trunk

pytest/plugin/_pytest.py

@@ -1,6 +1,6 @@
 import py
 
-from pytest.pluginmanager import HookRelay
+from pytest._core import HookRelay
 
 def pytest_funcarg___pytest(request):
     return PytestArg(request)

pytest/plugin/pytester.py

@@ -8,7 +8,7 @@ import re
 import inspect
 import time
 from fnmatch import fnmatch
-from pytest._config import Config as pytestConfig
+from pytest._core import Config as pytestConfig
 from pytest.plugin.session import Collection
 from py.builtin import print_
 
@@ -222,7 +222,6 @@ class TmpTestdir:
         """ this is used from tests that want to re-invoke parse(). """
         if not args:
             args = [self.tmpdir]
-        from pytest import _config
         oldconfig = py.test.config
         try:
             c = py.test.config = pytestConfig()