Merge pull request #2414 from Schpidi/symlinks_vb41

provider/virtualbox: automatically enable symlinks on vboxsf for VirtualBox 4.1

plugins/providers/virtualbox/driver/version_4_1.rb

@@ -427,7 +427,12 @@ module VagrantPlugins
               "--hostpath",
               folder[:hostpath]]
             args << "--transient" if folder.has_key?(:transient) && folder[:transient]
+
+            # Add the shared folder
             execute("sharedfolder", "add", @uuid, *args)
+
+            # Enable symlinks on the shared folder
+            execute("setextradata", @uuid, "VBoxInternal2/SharedFoldersEnableSymlinksCreate/#{folder[:name]}", "1")
           end
         end