More multicol and flexbox tests

Hi,

these last few days I've pushed a number of our multicol and flexbox tests  
(the author wishes to remain anonymous) through to the "submitted" point.  
I had hoped to examine them more closely myself, but I have a lot on my  
plate so it's probably more efficient to skip that step and open up for  
easier review and tracking by a wider audience (via Shepherd etc).

Currently, there are 102 new multicol tests awaiting review. (There are  
also 3 with known issues - missing references.)

Also, there are 199 new flexbox tests awaiting review. (There are 97 more,  
but they have not yet been given a "help" <link> - this will be rectified  
eventually)

-- 
Øyvind Stenhaug
Core Norway, Opera Software ASA