Sitemap allows for multiple redirects in getRedirectForxxx methods.
getRedirectForxxx methods renamed for consistency.
Fixed missing call to loadNodes() in
DefaultUserNavigationTree.loginStatusChange()

Fixed StandardPages - 'private', and therefore any of its children, was
not being displayed because it had no LabelKey.
SitemapChecker modified to ensure that a redirect target will not be
prevented from being visible by an ancestor having a missing label key

Changed 'permission' to 'role' (missed from earlier refactoring)

Changed DefaultRealm to use new page permission syntax of page:view:*

Corrected logic for loading nodes; login shown only when user not logged
in, logout never shown.  See #158, #157, #221  Testbench tests still required
Fixes #223
Test for authorisation failure.  Tests refactored to make login / logout
available in test case
Navigator is last to receive login status change.  Fixes #225
Added some browser back/forward tests.  All tests green
Added a couple of checkNotNulls to the Sitemap
Added authentication failure test
Closes #221