tox.ini: use testpaths, cleanup other pytest options

tox.ini

@@ -201,13 +201,13 @@ commands = python scripts/release.py {posargs}
 
 [pytest]
 minversion = 2.0
-plugins = pytester
-addopts = -ra -p pytester --ignore=testing/cx_freeze
-rsyncdirs = tox.ini pytest.py _pytest testing
+addopts = -ra -p pytester
+rsyncdirs = tox.ini doc src testing
 python_files = test_*.py *_test.py testing/*/*.py
 python_classes = Test Acceptance
 python_functions = test
-norecursedirs = .tox ja .hg cx_freeze_source testing/example_scripts
+testpaths = doc,testing
+norecursedirs = testing/example_scripts
 xfail_strict=true
 filterwarnings =
     error