Returns the active :class:`TaskDB` for the current project and task.

def active_db():
    """Returns the active :class:`TaskDB` for the current project and task.
    """
    global dbs
    # The task database is encapsulated in a class for easier serialization to
    # JSON. Get the DB for the (project, task) combination.
    dbkey = (project, task)
    if dbkey in dbs:
        taskdb = dbs[dbkey]
    else:
        taskdb = TaskDB()
        dbs[dbkey] = taskdb
        msg.okay("Initialized JSON database for {}.{}".format(*dbkey), 2)

    return taskdb