Turn turbolinks on by default for new apps

railties/lib/rails/generators/app_base.rb

@@ -226,7 +226,14 @@ module Rails
       end
 
       def javascript_gemfile_entry
-        "gem '#{options[:javascript]}-rails'" unless options[:skip_javascript]
+        unless options[:skip_javascript]
+          <<-GEMFILE
+            gem '#{options[:javascript]}-rails'
+            
+            # Turbolinks makes following links in your web application faster. Read more: https://github.com/rails/turbolinks
+            gem 'turbolinks'
+          GEMFILE
+        end
       end
 
       def javascript_runtime_gemfile_entry

railties/lib/rails/generators/rails/app/templates/Gemfile

@@ -9,14 +9,13 @@ source 'https://rubygems.org'
 <%= assets_gemfile_entry %>
 <%= javascript_gemfile_entry %>
 
-# Puts a simple HTTP cache in front of your app.
-# For large-scale production use, consider using a caching reverse proxy like nginx, varnish, or squid.
+# Puts a simple HTTP cache in front of your app (and gets you ready for later upgrading to nginx/varnish/squid)
 gem 'rack-cache', '~> 1.2'
 
 # To use ActiveModel has_secure_password
 # gem 'bcrypt-ruby', '~> 3.0.0'
 
-# To use Jbuilder templates for JSON
+# Build JSON APIs with ease. Read more: http://github.com/rails/jbuilder
 # gem 'jbuilder'
 
 # Use unicorn as the app server

railties/lib/rails/generators/rails/app/templates/app/assets/javascripts/application.js.tt

@@ -13,5 +13,6 @@
 <% unless options[:skip_javascript] -%>
 //= require <%= options[:javascript] %>
 //= require <%= options[:javascript] %>_ujs
+//= require turbolinks
 <% end -%>
 //= require_tree .