Skip various unsupported tests on Windows
Various fixes in the tests for Windows
Make sure tests/generic.py use the current dir to import Circus
Fix test_issues665 on non-Windows environments
Fix configure_logger in tests on Windows.
Added workaround for upstream Python bug.

See
https://bitbucket.org/hpk42/tox/issue/161/setting-pythonhashseed-can-crash.
Fixed string escape on Windows.
Skip failing stream tests on Python 2 and Windows
Convert env to byte dictionary on Python 2.
Prevent zombie processes with coverage run.