Squashed commit of the following:

Squashed commit of the following:

commit 255fa25a0a956ccac7b8a3c0434321bef3b67942
Author: Jesse Luehrs <doy@tozt.net>
Date:   Mon Jul 5 19:26:30 2010 -0500

    just close over the default value, stop fiddling with reparsing

commit e78f18dd84e155eccae4986de1de2d8adf0e4373
Author: Jesse Luehrs <doy@tozt.net>
Date:   Mon Jul 5 17:32:45 2010 -0500

    support default => undef better

commit 7be1d004a96a44cc93b0a85bdfb26e6be647e77d
Author: Jesse Luehrs <doy@tozt.net>
Date:   Mon Jul 5 17:24:49 2010 -0500

    refactor out default generation into something moose can use