Adding box_url as a possible option at vagrantfile

lib/vagrant/config.rb

@@ -96,6 +96,7 @@ module Vagrant
 
       attr_accessor :auto_port_range
       attr_accessor :box
+      attr_accessor :box_url
       attr_accessor :box_ovf
       attr_accessor :base_mac
       attr_accessor :boot_mode

test/test_helper.rb

@@ -32,6 +32,7 @@ class Test::Unit::TestCase
       config.ssh.private_key_path = '~/foo'
 
       config.vm.box = "foo"
+      config.vm.box_url = "http://mycompany.com/protected/my_box.box"
       config.vm.box_ovf = "box.ovf"
       config.vm.base_mac = "42"
       config.vm.disk_image_format = 'VMDK'