Refactors style sheets for new user dashboard,fixes spec test, pins to ...

...active fedora 7.1.0, refs #9622

Working on ScholarSphere technical debt. Moves new user dashboard layout into Sufia to eliminate overrides, moves styles into Sufia folder and uses @import per note in CSS file, but pins to active-fedora 7.1.0 to eliminate error.
How about `$dashboard-background`?