CLC-1809 DRY access to SASS vars in LiveStyles
https://jira.media.berkeley.edu/jira/browse/CLC-1809

Moving this to a back-end job simplifies a lot of code.
Christian, I can dry up the styles-ref.scss as well if we can get away with style="" attribs.
CLC-1809 Dry out Livestyle approach

- Color vars now named consistently throughout cc
- Livestyle now parses all .scss in assets/stylesheets
- File parsing is now more efficient (doesn't use markers)
CLC-1809 Livestyle tweaks
Merge pull request #1041 from shacker/CLC-1809c

CLC-1809 DRY access to SASS vars in LiveStyles