Use 127.0.0.1 instead of localhost for port use checking. [GH-1057]

Many systems actually don't have "localhost" setup as loopback in their
/etc/hosts file, so this would fail. This makes it pass.

CHANGELOG.md

@@ -38,6 +38,8 @@
     using SCP to upload files. [GH-924]
   - When console input is asked for (destroying a VM, bridged interfaces, etc.),
     keystrokes such as ctrl-D and ctrl-C are more gracefully handled. [GH-1017]
+  - Fixed bug where port check would use "localhost" on systems where
+    "localhost" is not available. [GH-1057]
 
 ## 1.0.3 (May 1, 2012)
 

lib/vagrant/action/vm/check_port_collisions.rb

@@ -33,7 +33,7 @@ module Vagrant
             hostport = options[:hostport].to_i
             hostport = current[options[:name]] if current.has_key?(options[:name])
 
-            if existing.include?(hostport) || is_port_open?("localhost", hostport)
+            if existing.include?(hostport) || is_port_open?("127.0.0.1", hostport)
               # We have a collision! Handle it
               send("handle_#{handler}".to_sym, options, existing)
             end