Fix some basic mistakes with commands

plugins/commands/box/command/root.rb

@@ -9,7 +9,7 @@ module VagrantPlugins
 
           @main_args, @sub_command, @sub_args = split_main_and_subcommand(argv)
 
-          @subcommands = Registry.new
+          @subcommands = Vagrant::Registry.new
           @subcommands.register(:add)       { Add }
           @subcommands.register(:list)      { List }
           @subcommands.register(:remove)    { Remove }

plugins/commands/reload/command.rb

@@ -5,7 +5,7 @@ module VagrantPlugins
     class Command < Vagrant::Command::Base
       # We assume that the `up` plugin exists and that we'll have access
       # to this.
-      include Vagrant::CommandUp::StartMixins
+      include VagrantPlugins::CommandUp::StartMixins
 
       def execute
         options = {}