Print information about .railsrc to users

railties/lib/rails/commands/application.rb

@@ -13,6 +13,7 @@ else
   if File.exist?(railsrc)
     extra_args_string = File.open(railsrc).read
     extra_args = extra_args_string.split(/\n+/).map {|l| l.split}.flatten
+    puts "Using #{extra_args.join(" ")} from #{railsrc}"
     ARGV << extra_args
     ARGV.flatten!
   end

railties/lib/rails/generators/rails/app/USAGE

@@ -2,6 +2,12 @@ Description:
     The 'rails new' command creates a new Rails application with a default
     directory structure and configuration at the path you specify.
 
+    You can specify extra command-line arguments to be used every time
+    'rails new' runs in the .railsrc configuration file in your home directory.
+
+    Note that the arguments specified in the .railsrc file don't affect the
+    defaults values shown above in this help message.
+
 Example:
     rails new ~/Code/Ruby/weblog