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-2737: Change Tools' web.xml files to comply with LAMS 2.4 Tool Application Context discovery mechanism. Add missing abstract methods implementation. Remove several libraries as they interfere with endorsed XML libraries on JBoss 5.