Set git clone depth to 10 for Travis to make it faster
Fixes #14443: Only transition what needs transitioning for thumbnails to avoid Safari/Chrome render bug
document that fieldset[disabled] is somewhat broken in IE11; fixes #14509
Merge pull request #14516 from twbs/fix-14509

Document that fieldset[disabled] is somewhat broken in IE11
Merge pull request #14497 from BBosman/clone-depth

Set git clone depth to 10 for Travis to make it faster