Vagrantfile: download precise32 box if missing
Vagrantfile: download precise32 box if missing

The config.vm.box_url setting is described here:
http://vagrantup.com/v1/docs/config/vm/box_url.html

The result:

	$ vagrant up
	[default] Box precise32 was not found. Fetching box from specified URL...
	[vagrant] Downloading with Vagrant::Downloaders::HTTP...
	[vagrant] Downloading box: http://files.vagrantup.com/precise32.box
	[vagrant] Extracting box...
	[vagrant] Verifying box...
	[vagrant] Cleaning up downloaded box...
	[default] Importing base box 'precise32'...
	...

rails/rails-dev-box,wstrinz/fof-box,ipmobiletech/rails-dev-box,diguage/rails-dev-box,oyuk/rails-dev-box,igormartire/rails-proj2,makersquare/student-dev-box,michaelw99/hw2-sp15,tingtingchiang/rorHW,wstrinz/fof-box,BastianHofmann/rails-vagrant,michaelw99/rails,Server4001/awesome_auctions,syoo11/hw2-sp15,lintangarief/rails-dev-box,alexc2684/rails-dev-box,yyyyaaa/cookit,ljrzarate/vagrant-rails,syoo11/hw2-sp15,isabelzhang/hw2-sp16,chubbyzz/rails-vagrant,michaelw99/hw2-sp15,oppai/manga-dev-box,isabelzhang/hw2-sp16,igormartire/rails-proj2,michaelw99/rails,yyyyaaa/cookit,yyyyaaa/cookit,koheisg/music_getter,sasselin/rails-dev-box,michaelw99/rails,alexc2684/rails-dev-box,Server4001/awesome_auctions,slamba10/rails_Sahil_Lamba,totzyuta/rails-dev-box,lyosha85/rails-dev-box,miguelff/rails-dev-box,aliismayilov/rails-dev-box,youkyll/rails-dev,isabelzhang/hw2-sp16,rails-decal/rails-dev-box,iDreamOn/rails-dev-box,dannyvassallo/rails-middleman-vagrant,tandemploy/rails-dev-box,michaelw99/rails,michaelw99/rails,danielalvarenga/rails-dev-box,isabelzhang/hw2-sp16,michaelw99/hw2-sp15,michaelw99/hw2-sp15,michaelw99/hw2-sp15,sasselin/rails-dev-box,tingtingchiang/rorHW,igorsamado/rails-dev-box,t4deu/ruby-dev-box,yyyyaaa/cookit,william-c-martin-iii/rails-app-dev-box,alexc2684/rails-dev-box,youkyll/rails-dev,wstrinz/fof-box,howardbonds/first-app,koheisg/music_getter,youkyll/rails-dev,igormartire/rails-proj2,ljrzarate/vagrant-rails,muhammadn/rails-dev-box-windows,neli2/amag-app,Server4001/awesome_auctions,ViniciusAtaide/Tcc,howardbonds/first-app,jgherder/rails-dev-box,slacker2/dev-in-rails-box,syoo11/hw2-sp15,slamba10/rails_Sahil_Lamba,syoo11/hw2-sp15,BastianHofmann/rails-vagrant,ViniciusAtaide/Tcc,igormartire/rails-proj2,Server4001/awesome_auctions,koheisg/music_getter,slamba10/rails_Sahil_Lamba,mba811/rails-dev-box,ViniciusAtaide/Tcc,padioca/dev-box,muhammadn/rails-dev-box-windows,bill-c-martin/rails-app-dev-box,andela-iokonkwo/rails-dev-box,neli2/amag-app,elektronaut/sugar-dev-box,slamba10/rails_Sahil_Lamba,syoo11/hw2-sp15,alexc2684/rails-dev-box,chubbyzz/rails-vagrant,41studio/rails-dev-box,tingtingchiang/rorHW,neli2/amag-app,youkyll/rails-dev,slacker2/dev-in-rails-box,neli2/amag-app,makersquare/student-dev-box,tingtingchiang/rorHW,howardbonds/first-app,yahonda/rails-dev-box,cyberid41/rails-dev-box