Joined Cases C-335/11 and C-337/11: Judgment of the Court (Second Chamber) of 11 April 2013 (request for a preliminary ruling from the Sø- og Handelsret, Denmark) — HK Danmark, acting on behalf of Jette Ring v Dansk almennyttigt Boligselskab (C-335/11) v HK Danmark, acting on behalf of Lone Skouboe Werge v Dansk Arbejdsgiverforening, acting on behalf of Pro Display A/S, in liquidation (C-337/11) (Social policy — United Nations Convention on the Rights of Persons with Disabilities — Directive 2000/78/CE — Equal treatment in employment and occupation — Articles 1, 2 and 5 — Difference in treatment on grounds of disability — Dismissal — Existence of a disability — Employee absent because of disability — Obligation to provide accommodation — Part-time work — Length of the period of notice)