Introduce a bit of sanity to talk/PRESUBMIT.py's license checking.

The comma this allows is a very common variant of the license header (3:1
preferred over the no-comma variant in talk/).

Also pacify pylint a bit, and correct a flagrantly incorrect header I happened
to come across.

BUG=2098,2133
R=henrike@webrtc.org, niklas.enbom@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/1866004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@4396 4adac7df-926f-26a2-2b94-8c16560cd09d

talk/site_scons/site_tools/talk_noops.py

@@ -16,5 +16,5 @@ def generate(env):
     )
     env.Append(BUILDERS={'RES': builder, 'Grit': builder})
 
-def exists(env):
+def exists(dummy):
   return 1