Improving migration generator

Hi,

I've submitted a patch to add new features to migration generator -
http://dev.rubyonrails.org/ticket/9166

It removes the previous functionality of auto generating migrations,
which generated migration that looked like :

add_column :accounts, :ssl_flag, :type, :null => :no?, :default => :maybe?

I didn't really find this useful as you will have to manually edit the
migration file in all the cases anyways.

With this patch, it enables you to directly run the migration in
common cases. So now when you do :

script/generate migration AddMoreToPost title:string body:text

It generates :

class AddMoreToPost < ActiveRecord::Migration
  def self.up
    add_column :posts, :title, :string
    add_column :posts, :body, :text
  end

  def self.down
    remove_column :posts, :body
    remove_column :posts, :title
  end
end