update the extension template to new class system

middleman-core/lib/middleman-core/templates/extension/Gemfile

@@ -6,14 +6,14 @@ source 'http://rubygems.org'
 gemspec
 
 group :development do
-  gem "rake",     "~> 0.9.2"
-  gem "rdoc",     "~> 3.9"
-  gem "yard",     "~> 0.8.0"
+  gem "rake"
+  gem "rdoc"
+  gem "yard"
 end
 
 group :test do
-  gem "cucumber", "~> 1.2.0"
+  gem "cucumber"
   gem "fivemat"
-  gem "aruba",    "~> 0.4.11"
-  gem "rspec",    "~> 2.7"
+  gem "aruba"
+  gem "rspec"
 end

middleman-core/lib/middleman-core/templates/extension/gitignore

@@ -1,2 +1,5 @@
 # Ignore bundler lock file
-Gemfile.lock
+/Gemfile.lock
+
+# Ignore pkg folder
+/pkg

middleman-core/lib/middleman-core/templates/extension/lib/lib.rb

@@ -2,19 +2,16 @@
 require "middleman-core"
 
 # Extension namespace
-module MyExtension < Middleman::Extension
+class MyExtension < ::Middleman::Extension
   option :my_option, "default", "An example option"
 
-  def initialize(app, options_hash={})
+  def initialize(app, options_hash={}, &block)
     # Call super to build options from the options_hash
     super
 
     # Require libraries only when activated
     # require 'necessary/library'
 
-    # Include helpers or instance methods for the Middleman app
-    # app.send :include, Helpers
-
     # set up your extension
     # puts options.my_option
   end
@@ -23,7 +20,11 @@ module MyExtension < Middleman::Extension
     # Do something
   end
 
-  # module Helpers
+  # A Sitemap Manipulator
+  # def manipulate_resource_list(resources)
+  # end
+
+  # module do
   #   def a_helper
   #   end
   # end
@@ -32,9 +33,7 @@ end
 
 # Register extensions which can be activated
 # Make sure we have the version of Middleman we expect
-# ::Middleman::Extensions.register(:extension_name) do
-#
-#   # Return the extension class
-#   ::MyExtension
-#
-# end
+# Name param may be omited, it will default to underscored
+# version of class name
+
+# MyExtension.register(:my_extension)