Added logout button

Logout button was added to Web UI.

Click on logout button executes session_logout command. If command succeeds or xhr stutus is 401 (unauthorized - already logged out) page is redirected to logout.html.

logout.html is a simple page with "You have been logged out" text and a link to return back to main page.

https://fedorahosted.org/freeipa/ticket/2363

freeipa.spec.in

@@ -555,6 +555,7 @@ fi
 %{_usr}/share/ipa/migration/migration.py*
 %dir %{_usr}/share/ipa/ui
 %{_usr}/share/ipa/ui/index.html
+%{_usr}/share/ipa/ui/logout.html
 %{_usr}/share/ipa/ui/*.ico
 %{_usr}/share/ipa/ui/*.css
 %{_usr}/share/ipa/ui/*.js
@@ -674,6 +675,9 @@ fi
 %ghost %attr(0644,root,apache) %config(noreplace) %{_sysconfdir}/ipa/ca.crt
 
 %changelog
+* Wed Feb 29 2012 Petr Vobornik <pvoborni@redhat.com> - 2.99.0-20
+- Add Web UI logout page
+
 * Mon Feb 27 2012 Rob Crittenden <rcritten@redhat.com> - 2.99.0-19
 - Add Requires to ipa-client on oddjob-mkhomedir