New: Added themable attribute for divider thickness in table header view
Merge branch 'master' of https://github.com/cappuccino/cappuccino into table_header_divider_thickness
Fixed: Added theme attribute 'divider-thickness' to wrong class when doing manual merge.
Merge pull request #1970 from mrcarlberg/table_header_divider_thickness

New: Added themable attribute for divider thickness in table header view