dropdown header and disabled link colors (and refactor commenting styles)

BS3 commit 58b90dae1570eca6c921933742bf418ebf3ee47b
forms

BS3 commit 83f1a75e7a8ae4570641f1fcf88c2062373fff62
input group background var

BS3 commit a66cdb0c304b701c299bdbf24a53dd6105d4429d
fixes 8983

BS3 commit 92c2ad98e753c64a2bd6e3fb94870a2ad3ee0333