Make bundler work under Rubygems 1.3.5.

This does not actually downgrade the required version of Rubygems,
but does make it possible for brave souls who wish to override the
restriction to do so.

Rakefile

@@ -33,7 +33,7 @@ end
 
 # Rubygems 1.3.5, 1.3.6, and HEAD specs
 rubyopt = ENV["RUBYOPT"]
-%w(master REL_1_3_6).each do |rg|
+%w(master REL_1_3_5 REL_1_3_6).each do |rg|
   desc "Run specs with Rubygems #{rg}"
   Spec::Rake::SpecTask.new("spec_gems_#{rg}") do |t|
     t.spec_files = FileList['spec/**/*_spec.rb']

lib/bundler/dependency.rb

@@ -1,4 +1,5 @@
 require 'rubygems/dependency'
+require 'bundler/shared_helpers'
 
 module Bundler
   class Dependency < Gem::Dependency