Remove the dotfile_name configuration option.

The dotfile is gone now so the configuration option is obselete

config/default.rb

@@ -1,6 +1,5 @@
 Vagrant.configure("2") do |config|
   # default config goes here
-  config.vagrant.dotfile_name = ".vagrant"
   config.vagrant.host = :detect
 
   config.ssh.username = "vagrant"

plugins/kernel_v1/config/vagrant.rb

@@ -12,8 +12,9 @@ module VagrantPlugins
       end
 
       def upgrade(new)
-        new.vagrant.dotfile_name = @dotfile_name if @dotfile_name != UNSET_VALUE
         new.vagrant.host = @host if @host != UNSET_VALUE
+
+        # TODO: Warn that "dotfile_name" is gone in V2
       end
     end
   end

plugins/kernel_v2/config/vagrant.rb

@@ -3,7 +3,6 @@ require "vagrant"
 module VagrantPlugins
   module Kernel_V2
     class VagrantConfig < Vagrant.plugin("2", :config)
-      attr_accessor :dotfile_name
       attr_accessor :host
     end
   end

test/unit/vagrant/environment_test.rb

@@ -158,26 +158,26 @@ VF
       environment = isolated_environment do |env|
         env.vagrantfile(<<-VF)
 Vagrant.configure("2") do |config|
-  config.vagrant.dotfile_name = "foo"
+  config.ssh.port = 200
 end
 VF
       end
 
       env = environment.create_vagrant_env
-      env.config_global.vagrant.dotfile_name.should == "foo"
+      env.config_global.ssh.port.should == 200
     end
 
     it "should load from a custom Vagrantfile" do
       environment = isolated_environment do |env|
         env.file("non_standard_name", <<-VF)
 Vagrant.configure("2") do |config|
-  config.vagrant.dotfile_name = "custom"
+  config.ssh.port = 200
 end
 VF
       end
 
       env = environment.create_vagrant_env(:vagrantfile_name => "non_standard_name")
-      env.config_global.vagrant.dotfile_name.should == "custom"
+      env.config_global.ssh.port.should == 200
     end
 
   end
@@ -323,7 +323,6 @@ VF
         env.vagrantfile(<<-VF)
 Vagrant.configure("2") do |config|
   config.ssh.port = 1
-  config.vagrant.dotfile_name = "foo"
   config.vm.box = "base"
 
   config.vm.define "vm1" do |inner|
@@ -338,7 +337,7 @@ VF
       env = environment.create_vagrant_env
       machine = env.machine(:vm1, :foo)
       machine.config.ssh.port.should == 100
-      machine.config.vagrant.dotfile_name.should == "foo"
+      machine.config.vm.box.should == "base"
     end
 
     it "should load the box configuration for a V2 box" do