Getting rid of the completedList and completedIds, instead only
using the 'completed' attribute of the todo task. This fixes some
issues were a task was at the same time in the todoIds and
completedIds.
Updating the task list cleanup to not restore the completedIds list.
Fixing the mocha test to not check for the completedIds.
Merge pull request #226 from toebu/completed-todos-fix

Getting rid of the completedList and completedIds