#736: Breadcrumbs: don't link if show action is disabled

This resolves #736 by simply displaying the result of `display_name` if
the show action is disabled, instead of attempting to link to the
resource in question.
More useful `actions` method for `index_as_table`
correct mistakes
don't forget for backwards compatibility

for :name option
Merge pull request #3020 from mindhalt/patch-3

More useful `actions` method for `index_as_table`
updates to #3020

Also: adds a test!

For some reason `rake docs:build` is failing…?