Move common support code from the base migration to a library file where

it can be used by other migrations.

db/migrate/001_create_osm_db.rb

@@ -1,38 +1,4 @@
-module ActiveRecord
-  module ConnectionAdapters
-    module SchemaStatements
-      def add_primary_key(table_name, column_name, options = {})
-        index_name = options[:name]
-        column_names = Array(column_name)
-        quoted_column_names = column_names.map { |e| quote_column_name(e) }.join(", ")
-        execute "ALTER TABLE #{table_name} ADD PRIMARY KEY #{quote_column_name(index_name)} (#{quoted_column_names})"
-      end
-
-      alias_method :old_add_column_options!, :add_column_options!
-
-      def add_column_options!(sql, options)
-        old_add_column_options!(sql, options)
-        sql << " #{options[:options]}"
-      end
-
-      alias_method :old_options_include_default?, :options_include_default?
-
-      def options_include_default?(options)
-        old_options_include_default?(options) && !(options[:options] =~ /AUTO_INCREMENT/i)
-      end
-    end
-
-    class MysqlAdapter
-      alias_method :old_native_database_types, :native_database_types
-
-      def native_database_types
-        types = old_native_database_types
-        types[:bigint] = { :name => "bigint", :limit => 20 }
-        types
-      end
-    end
-  end
-end
+require 'lib/migrate'
 
 class CreateOsmDb < ActiveRecord::Migration
   def self.up