LDEV-3275: Decrease version of Hibernate from 4.x (delivered to WildFly) to 3.6.10 (newer than used before, but still 3.x as otherwise Spring won't work with it).
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: Add single activity lessons wizard, first implementation iteration. Some changes were not committed as they interfere with old index page design.