* E402: we exectute code between imports, like modifying 'sys.path' in the tests
* E731: we assign to lambdas in a lot of places, we may want to consider defining functions in a single line instead (what pep8 recommends)
* setup.py: the '__version__' variable is not defined in the script, it is loadded from youtube_dl/version.py
* devscripts/buildserver.py: Produces a lot of messages