[mediaqueries] RESOLVED: 'not', 'only', 'and', 'or' are invalid media types

Earlier, we resolved that 'not', 'only', 'and', 'or' are invalid media  
types.

I've updated the media queries level 4 spec to reflect that resolution:
https://dvcs.w3.org/hg/csswg/diff/0acc2d14a62b/mediaqueries/Overview.src.html

and created a couple of tests:
http://test.csswg.org/shepherd/search/author/florian/title/syntax%20error%20handling%20in%20Media%20Queries/

All browsers fail the test that relates to 'or' being invalid.  
Webkit/Blink and Presto pass the rest, but Gecko fails (I couldn't test  
IE).

I was wondering if we should also errata MQ level 3, and if yes, what the  
work flow for doing that is.

  - Florian