Create DeepFreeze refinement for use in definables

[bryanp]

The Definable module freezes the object once an instance is created, but the object itself must implement freeze and freeze its own state. I'd like to add a DeepFreeze refinement to pakyow/support that will be used instead. DeepFreeze will call deep_freeze on any ivars defined on the object, then freeze itself. We should also be able to remove the freeze definitions on Router and Route.

[jphager2]

can this one be removed to? https://github.com/pakyow/pakyow/blob/environment/pakyow-support/lib/pakyow/support/configurable/config.rb#L37

[jphager2]

Looks like there will be a problem with freezing all ivars. A Pakyow::App has stores the Rack::Builder in an ivar, and that cant be frozen apparently.

Maybe we can have an UNFREEZABLE list a la deep_dup's UNDUPABLE.

[bryanp]

I think unfreezable makes sense, but maybe defined on the scope being refined? That would let Pakyow::App register the @builder ivar as being unfreezable.

[jphager2]

ok I made an update to the pull request.