Remove sub-theme specific CSS

cm_theme was originally developed for channelAustin. There is still some CSS that I don't think is used on many other sites, since it depends on manually added blocks such as the ones in the subheader region at www.channelaustin.org (channel-icons-schedule, channel-icons-block and the social media block).

These should probably be removed from cm_theme and added to a site-specific sub-theme instead, unless these blocks somehow are included in the starterkit profiles (or features), for others to use easily.