Fork-and-wait on Tiger as well as leopard. [related to GH-51]

lib/vagrant/ssh.rb

@@ -42,7 +42,7 @@ module Vagrant
       # (GH-51). As a workaround, we fork and wait. On all other platforms,
       # we simply exec.
       pid = nil
-      pid = fork if Util::Platform.leopard?
+      pid = fork if Util::Platform.leopard? || Util::Platform.tiger?
       Kernel.exec "ssh #{command_options.join(" ")} #{options[:username]}@#{options[:host]}".strip if pid.nil?
       Process.wait(pid) if pid
     end

lib/vagrant/util/platform.rb

@@ -5,8 +5,12 @@ module Vagrant
     # This class just contains some platform checking code.
     class Platform
       class << self
+        def tiger?
+          platform.include?("darwin8")
+        end
+
         def leopard?
-          RUBY_PLATFORM.downcase.include?("darwin9")
+          platform.include?("darwin9")
         end
 
         [:darwin, :bsd, :linux].each do |type|