core: Kick off a vagrant-backports lib with method for verifying vagrant version

lib/vagrant-backports/README.md

@@ -0,0 +1,10 @@
+# vagrant-backports
+
+<!--
+[![Build Status](https://travis-ci.org/fgrehm/vagrant-backports.png?branch=master)](https://travis-ci.org/fgrehm/vagrant-backports) [![Gem Version](https://badge.fury.io/rb/vagrant-backports.png)](http://badge.fury.io/rb/vagrant-backports) [![Code Climate](https://codeclimate.com/github/fgrehm/vagrant-backports.png)](https://codeclimate.com/github/fgrehm/vagrant-backports) [![Coverage Status](https://coveralls.io/repos/fgrehm/vagrant-backports/badge.png?branch=master)](https://coveralls.io/r/fgrehm/vagrant-backports) [![Gittip](http://img.shields.io/gittip/fgrehm.svg)](https://www.gittip.com/fgrehm/)
+-->
+
+A "soon to be extracted" gem that helps Vagrant plugin developers to stay sane
+when keeping up with Vagrant improvements and backwards incompatible changes.
+
+More information coming out soon...

lib/vagrant-backports/utils.rb

@@ -0,0 +1,9 @@
+module Vagrant
+  module Backports
+    class << self
+      def vagrant_1_3_or_later?
+        Gem::Version.new(Vagrant::VERSION) >= Gem::Version.new('1.3.0')
+      end
+    end
+  end
+end

lib/vagrant-lxc/action.rb

@@ -20,9 +20,8 @@ require 'vagrant-lxc/action/setup_package_files'
 require 'vagrant-lxc/action/share_folders'
 require 'vagrant-lxc/action/warn_networks'
 
-unless Vagrant::LXC.vagrant_1_3_or_later
-  require 'vagrant-lxc/action/wait_for_communicator'
-  Vagrant::Action::Builtin.const_set :WaitForCommunicator, Vagrant::LXC::Action::WaitForCommunicator
+unless Vagrant::Backports.vagrant_1_3_or_later?
+  require 'vagrant-backports/action/wait_for_communicator'
 end
 
 module Vagrant
@@ -157,7 +156,7 @@ module Vagrant
                 b3.use Builtin::EnvSet, :force_halt => true
                 b3.use action_halt
                 b3.use Destroy
-                if Vagrant::LXC.vagrant_1_3_or_later
+                if Vagrant::Backports.vagrant_1_3_or_later?
                   b3.use Builtin::ProvisionerCleanup
                 end
               else

lib/vagrant-lxc/plugin.rb

@@ -1,4 +1,5 @@
-require "vagrant"
+require 'vagrant'
+require 'vagrant-backports/utils'
 
 module Vagrant
   module LXC
@@ -23,9 +24,5 @@ module Vagrant
         Config
       end
     end
-
-    def self.vagrant_1_3_or_later
-      Gem::Version.new(Vagrant::VERSION) >= Gem::Version.new('1.3.0')
-    end
   end
 end