Updating NEWS for 2.26

[Carlos O'Donell]

On 07/03/2017 10:07 AM, Joseph Myers wrote:
> The NEWS section for security-related changes in 2.26 seems very 
> incomplete, with only a single entry.  It clearly needs to be filled out.  
> If people know of other significant changes missing from the main NEWS 
> section for 2.26, they should add those as well.
 
I noticed this also. I'm going to checkin some items after I finish two
more patch reviews.

-- 
Cheers,
Carlos.