Added Vagrantfile for building deb in vm.

This should help in automating binary package creation.

'make package' will make the package.
'make package COMMIT=blah' will make the package from commit blah.

deb/Makefile

@@ -0,0 +1,8 @@
+COMMIT?=HEAD
+
+.PHONY: package
+
+package:
+	vagrant up
+	vagrant ssh -c 'rm -rf pandoc && git clone https://github.com/jgm/pandoc && cd pandoc && git checkout -b work $(COMMIT) && git submodule update --init && ./make_deb.sh && cp *.deb /vagrant_data/'
+	vagrant halt

deb/Vagrantfile

@@ -0,0 +1,73 @@
+# -*- mode: ruby -*-
+# vi: set ft=ruby :
+
+# All Vagrant configuration is done below. The "2" in Vagrant.configure
+# configures the configuration version (we support older styles for
+# backwards compatibility). Please don't change it unless you know what
+# you're doing.
+Vagrant.configure(2) do |config|
+  # The most common configuration options are documented and commented below.
+  # For a complete reference, please see the online documentation at
+  # https://docs.vagrantup.com.
+
+  # Every Vagrant development environment requires a box. You can search for
+  # boxes at https://atlas.hashicorp.com/search.
+  config.vm.box = "ubuntu/trusty64"
+
+  # Disable automatic box update checking. If you disable this, then
+  # boxes will only be checked for updates when the user runs
+  # `vagrant box outdated`. This is not recommended.
+  # config.vm.box_check_update = false
+
+  # Create a forwarded port mapping which allows access to a specific port
+  # within the machine from a port on the host machine. In the example below,
+  # accessing "localhost:8080" will access port 80 on the guest machine.
+  # config.vm.network "forwarded_port", guest: 80, host: 8080
+
+  # Create a private network, which allows host-only access to the machine
+  # using a specific IP.
+  # config.vm.network "private_network", ip: "192.168.33.10"
+
+  # Create a public network, which generally matched to bridged network.
+  # Bridged networks make the machine appear as another physical device on
+  # your network.
+  # config.vm.network "public_network"
+
+  # Share an additional folder to the guest VM. The first argument is
+  # the path on the host to the actual folder. The second argument is
+  # the path on the guest to mount the folder. And the optional third
+  # argument is a set of non-required options.
+  config.vm.synced_folder ".", "/vagrant_data"
+
+  # Provider-specific configuration so you can fine-tune various
+  # backing providers for Vagrant. These expose provider-specific options.
+  # Example for VirtualBox:
+  #
+  config.vm.provider "virtualbox" do |vb|
+    # Display the VirtualBox GUI when booting the machine
+    # vb.gui = true
+
+    # Customize the amount of memory on the VM:
+    vb.memory = "4096"
+  end
+  #
+  # View the documentation for the provider you are using for more
+  # information on available options.
+
+  # Define a Vagrant Push strategy for pushing to Atlas. Other push strategies
+  # such as FTP and Heroku are also available. See the documentation at
+  # https://docs.vagrantup.com/v2/push/atlas.html for more information.
+  # config.push.define "atlas" do |push|
+  #   push.app = "YOUR_ATLAS_USERNAME/YOUR_APPLICATION_NAME"
+  # end
+
+  # Enable provisioning with a shell script. Additional provisioners such as
+  # Puppet, Chef, Ansible, Salt, and Docker are also available. Please see the
+  # documentation for more information about their specific syntax and use.
+  config.vm.provision "shell", inline: <<-SHELL
+    wget -q -O- https://s3.amazonaws.com/download.fpcomplete.com/debian/fpco.key | sudo apt-key add -
+    echo 'deb http://download.fpcomplete.com/ubuntu/trusty stable main'|sudo tee /etc/apt/sources.list.d/fpco.list
+    sudo apt-get update
+    sudo apt-get install -y stack build-essential debhelper dh-make
+  SHELL
+end