replace combustion engine testing with engine_cart
remove ruby 1.8 compatible logic
sidebar_items is deprecated; just render the search help under the form.
move spec/acceptance to spec/features
use a named route to the advanced search page, instead of constructing it from params.
query_has_constraints? is now used in blacklight 4.x to decide whether to render the constraints block at all. Make sure our overrides will be displayed if we're possibly doing an advanced search.
add a travis.yml file