Make more tests pass on Windows.

Also fix a few issues found along the way.

Tests had regressed a lot. Add a lot of tweaks to make most test pass.

R=dpranke@chromium.org
BUG=
TEST=

Review URL: http://codereview.chromium.org/6792060

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@80618 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/subprocess2.py b/subprocess2.py
index acba499..77fda58 100644
--- a/subprocess2.py
+++ b/subprocess2.py
@@ -51,7 +51,7 @@
   """Kills a process by its process id."""
   try:
     # Unable to import 'module'
-    # pylint: disable=F0401
+    # pylint: disable=E1101,F0401
     import signal
     return os.kill(pid, signal.SIGKILL)
   except ImportError:
@@ -105,6 +105,8 @@
 
   Returns None if it is unnecessary.
   """
+  if sys.platform == 'win32':
+    return None
   env = env or os.environ
 
   # Test if it is necessary at all.