Revert "Automate required vagrant plugin installation for any number of plugins."

vagrant/base/analyticstack/Vagrantfile

 Vagrant.require_version ">= 1.8.7"
-require_relative '../../vagrantplugins'
-install_plugins(['vagrant-vbguest'])
+unless Vagrant.has_plugin?("vagrant-vbguest")
+  raise "Please install the vagrant-vbguest plugin by running `vagrant plugin install vagrant-vbguest`"
+end
 
 VAGRANTFILE_API_VERSION = "2"
 

vagrant/base/cluster/Vagrantfile

 # -*- mode: ruby -*-
+
 # vi: set ft=ruby :
 
 VAGRANTFILE_API_VERSION = "2"

vagrant/base/devstack/Vagrantfile

 Vagrant.require_version ">= 1.8.7"
-require_relative '../../vagrantplugins'
-install_plugins(['vagrant-vbguest'])
+unless Vagrant.has_plugin?("vagrant-vbguest")
+  raise "Please install the vagrant-vbguest plugin by running `vagrant plugin install vagrant-vbguest`"
+end
 
 VAGRANTFILE_API_VERSION = "2"
 

vagrant/release/analyticstack/Vagrantfile

 Vagrant.require_version ">= 1.8.7"
-require_relative '../../vagrantplugins'
-install_plugins(['vagrant-vbguest'])
-
+unless Vagrant.has_plugin?("vagrant-vbguest")
+  raise "Please install the vagrant-vbguest plugin by running `vagrant plugin install vagrant-vbguest`"
+end
 
 VAGRANTFILE_API_VERSION = "2"
 

vagrant/release/devstack/Vagrantfile

 Vagrant.require_version ">= 1.8.7"
-require_relative '../../vagrantplugins'
-install_plugins(['vagrant-vbguest'])
+unless Vagrant.has_plugin?("vagrant-vbguest")
+  raise "Please install the vagrant-vbguest plugin by running `vagrant plugin install vagrant-vbguest`"
+end
 
 VAGRANTFILE_API_VERSION = "2"
 

vagrant/vagrantplugins.rb

-# Don't check for plugins on certain subcommands of vagrant.
-def is_check_necessary
-    exempt = ['help', 'plugin', 'version']
-    return ARGV.any? ? (ARGV & exempt).empty? : false
-end
-
-def install_plugins(plugins)
-    if not is_check_necessary
-        exit
-    end
-
-    not_installed = get_not_installed(plugins)
-    if not_installed.any?
-        puts "The following required plugins must be installed:"
-        puts "'#{not_installed.join("', '")}'"
-        print "Install? [y]/n: "
-        unless STDIN.gets.chomp == "n"
-            not_installed.each { |plugin| install_plugin(plugin) }
-        else
-            exit
-        end
-        $? ? continue : raise('Plugin installation failed, see errors above.')
-    end
-end
-
-def get_not_installed(plugins)
-    not_installed = []
-    plugins.each do |plugin|
-        unless Vagrant.has_plugin?(plugin)
-            not_installed << plugin
-        end
-    end
-    return not_installed
-end
-
-def install_plugin(plugin)
-    system "vagrant plugin install #{plugin}"
-end
-
-# If plugins successfully installed, restart vagrant to detect changes.
-def continue
-    exec "vagrant #{ARGV.join(' ')}"
-end
-