rename AppPreparer

AppPreparer doesn't actually prepare applications, it scrubs ARGV.
Let's also get the class under test while we're at it

railties/lib/rails/commands/application.rb

@@ -13,5 +13,5 @@ def self.exit_on_failure?
   end
 end
 
-Rails::Generators::AppPreparer.new(ARGV).prepare!
+Rails::Generators::ARGVScrubber.new(ARGV).prepare!
 Rails::Generators::AppGenerator.start

railties/lib/rails/generators/app_base.rb

@@ -5,6 +5,7 @@
 require 'rbconfig'
 require 'open-uri'
 require 'uri'
+require 'rails/generators/base'
 
 module Rails
   module Generators

railties/lib/rails/generators/base.rb

@@ -7,6 +7,7 @@
   exit
 end
 
+require 'rails/generators'
 require 'rails/generators/actions'
 
 module Rails

railties/lib/rails/generators/rails/app/app_generator.rb

@@ -311,7 +311,7 @@ def get_builder_class
     #
     # This class should be called before the AppGenerator is required and started
     # since it configures and mutates ARGV correctly.
-    class AppPreparer # :nodoc
+    class ARGVScrubber # :nodoc
       attr_reader :argv
 
       def initialize(argv = ARGV)
@@ -329,7 +329,7 @@ def prepare!
       private
 
         def handle_version_request!(argument)
-          if ['--version', '-v'].include?(argv.first)
+          if ['--version', '-v'].include?(argument)
             require 'rails/version'
             puts "Rails #{Rails::VERSION::STRING}"
             exit(0)