Mitchell Hashimoto 912e4974db Registry will now cache result values.
This is actually required so that we can do things like this
in plugins:

Vagrant.actions[:up].insert(Foo, Bar)
2012-01-28 17:31:50 -08:00
..
2011-12-24 22:25:02 -08:00
2011-12-26 17:38:47 -08:00