javascript fetches empty changelog from server
append an id to the change log after scheduling a class
changed unique id to timestamp and insert room data into change log
schedules classes from changelog (but doesn't unschedule old versions)
backend support for unassigning classes
some back-end tests for change log
setup for selenium browser tests
UI tests able to log in
factored out ajaxschedulingmoduletestbase
server side tests all passing