Added the ability to copy assessments from one cohort/class list to another (or the same one, where they are simply appended to the end of the list).
Merge branch 'develop' of https://github.com/EntradaProject/entrada-1x into develop

# By Robert Fotino (1) and Ryan Warner (1)
# Via Robert Fotino
* 'develop' of https://github.com/EntradaProject/entrada-1x:
  Refs #513, fixes "daily" frequency for recurring events.
  Updates LDAP sync script to no longer create cohorts, and adds handling for when a cohort doesn't exist.