Reviewed filters-displacement-02-f.svg test

Hi Chris,

I've reviewed your filters-displacement-02-f.svg testcase, adding pass  
criteria and some more testcase description text. Please verify that the  
changes are ok, I've marked the test as reviewed for now. I noted that  
firefox displayed the bottom gradient with a reddish tint applied (making  
it look different from the top gradient which is using essentially the  
same filter).

Cheers
/Erik

P.S. As a side-effect of reviewing, I also noticed that we had lost some  
information that was visible in the old 1.1 spec. Default values that were  
shown in the DTD snippets are not there anymore since we use the new spec  
style for elements. I updated the 1.1F2 spec to explicitly mention the  
default values for xChannelSelector and yChannelSelector [2].

[1] http://dev.w3.org/SVG/profiles/1.1F2/test/svg/filters-displace-02-f.svg
[2]  
http://dev.w3.org/SVG/profiles/1.1F2/publish/filters.html#feDisplacementMapXChannelSelectorAttribute

-- 
Erik Dahlstrom, Core Technology Developer, Opera Software
Co-Chair, W3C SVG Working Group
Personal blog: http://my.opera.com/macdev_ed