Remove Rails 3 conditional and code cleanup
Remove respond_to? method from lib/ransack/search.rb
Refactor form_builder with PR #317 default attribute & predicate via options[:default]

Affects `predicate_select` and `attribute_select`
Catch up with commits on master from PR #316 and #317

PR #316 related with #159: remove `respond_to?` from Ransack::Search
PR #317 Allow specifying default attribute and predicate via
options[:default]
Code cleanup
Remove unneeded arg from form_builder_spec.rb