Warning on leaving resource editing page (2.2.11)

Now the warning on leaving a resource editing page when changes have not yet been saved almost works as expected. The one last nit-picky issue is that the warning is displayed when changing the template. This makes sense, since we are literally leaving the page to register the new template and display any TVs for the new template, but it's not really appropriate - in fact, it's rather alarming and somewhat confusing at that point.