Update grunt-csscomb dependency

BS3 commits: f1d4a3bb5cb40cb81c18730d4c2ab8ef5b8dc3fe
Drop remaining leading commas

BS3 commits: e1bd300f2f38a32a5baccfcd5dcd83577b7960aa
add new variables for "pagination" to improve support of customizing

BS3 commits: 810c7ec4f8004129b88eba4aee15475d5d6f79ba