Hi,
This is my first post, and I hope not doing it wrong.
Just to notify that, according to my test, when you insert a picture on a page with the URL, it seems the code generated does not include the "alt" balise, with result in the page is not W3C compliant.
It's not critical, but maybe something could be done in the next release.
Anyway, congratulations for all the work done !
PS : silverstripe 3.1.2