user-private views.  Use it="${app}" for Manage Hudson and New Job links,
so these check the proper permission.  Replaced !it.isDefault() check
with new ViewGroup.canDelete API call.. Hudson ViewGroup uses isDefault()
for this method; MyViewsProperty checks views.size() > 1 so link is
hidden when there is only one user-private view.
Used !=false in jelly for backward compatibility (if a plugin implements
ViewGroup but does not have canDelete, null!=false will result in true).


git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@32319 71c3de6d-444a-0410-be80-ed276b4c234a