LDEV-3171: Give a Monitor an option to remove learner's content from activities when moving him backwards in a sequence. Implementation of content-removing method for most of tools.
LDEV-3070: Fix few minor errors in Tools. Pass notifyCloseURL to proper authoring page in some Tools. Make generation of Tool content a non read-only operation as it starts a database transaction which is later used for writing.
LDEV-2374: - Vote now accepts nominations created by Teacher as well as ones derived from input. - Teacher can now limit number of Learners contributing to Vote's nomination pool. - Each tool now declares which DataOutputDefinitions it can accept for Data Flow.