implement RCA Now editor index page
insert RCA Now in left menu in place of Explorer / Search
Add 'My page' item
Hide unwanted actions from the RCA Now / Student page listings
add hooks to redirect students back to the homepage / rca now index after editing
styling fixes for student page listings
restructure admin homepage as pluggable panels
add hook to override homepage panels, and hide site_summary from students
Merge branch 'feature/rcanow' into staging