exclude new fancy errors from pep8 check

- ./util/cythonpp.py:19:1: E731 do not assign a lambda expression, use a def
- ./gevent/pywsgi.py:401:13: E266 too many leading '#' for block comment
- everywhere: E402 module level import not at top of file

.pep8

 [pep8]
-ignore=E702,E265
+ignore=E702,E265,E402,E731,E266
 max_line_length=160
 exclude=.git,build,2.6,2.7,2.7pypy,3.3,test_support.py,test_queue.py,patched_tests_setup.py,test_threading_2.py,lock_tests.py