mention lack of support for split button dropdowns in vertical button groups
mention lack of support for split button dropdowns in vertical button groups

BS3 commits: fd4130534f6453bbe9c306cfd0869ee6599394b1

up2vs/todc-bootstrap,todc/todc-bootstrap,2947721120/googlebt4,ztx1491/todc-bootstrap,todc/todc-bootstrap,aaroncnhk/todc-bootstrap,2947721120/todc-bootstrap,todc/todc-bootstrap,mozillo/todc-bootstrap