Expose Rails.application.assets_manifest
Use old .dir
Merge branch 'manifest-api' into 2.x
Release 2.2.2
Merge branch '2.x'

Conflicts:
	CHANGELOG.md
	lib/sprockets/rails/version.rb
	lib/sprockets/railtie.rb
	sprockets-rails.gemspec
	test/test_railtie.rb