LDEV-2782: Leave traffic lights icon no matter if dependencies exist or not. Allow adding dependencies. Nicer layout for conditions thickbox. Remove unnecessary changes in CSS pages as they are inherited from defaultHTML.css.
LDEV-2782: Rename table with lesson condtions for better reflection of its function. Add icon and thickbox on Index page, showing release conditions of given lesson. Allow removing conditions.
LDEV-2782: Add backend code for conditional release of lessons. Prevent learners from accessing unreleased lessons. Inform learners of unlocked lessons after completing preceding lessons.
LDEV-2771: Prevent Single Sing On mechanism from constantly creating and removing SSO ID and cookie in case of unsuccessful login. Clean up unnecessary SSO cookie creation just after its removal in SessionManager.
LDEV-2740: Display all learning libraries, not only valid tools, in "Tool Management" sysadmin page. Add column for enabling/disabling libraries from that page. Remove "Learning Library Management" sysadmin page completely. Some code clean up.
LDEV-2450: Move SQL code to a patch of higher version. This code should fix a bug when upgrading to 2.3.5 version, but it still exists in DB coming from LAMS 2.3.5, so it needs to be applied when upgrading to 2.4. Also update several configuration entries in DB (information about module versions).