Features export support

I want to use this on a big deployment.
Big deployments get feature-driven.
So I need to export (and import) the settings from the rules table.

Here's how it happens:

A feature (called node_breadcrumb_rule) gets exposed in the features UI (thanks to hook_features_api)
You select which rules to export. currently they are just numbered, as there is no machine_name or label we can use. Yet.
Create your feature.
Deploy it to where you want
SHOULD work.

The menu link ID is NOT safe to transfer between sites, so I serialize the MENU LINK PATH in the export, and resolve it back to a local equivalent if I can when importing.
Currently - there is potential for clashes with the rule ID from one site to another (need machine_names)

But ... this will work for me for now. I can deploy a site feature or install profile that pre-configures with my preferred node_breadcrumb rules.
Some improvements/abstraction in the CRUD of the settings (node_breadcrumb_rule_save() etc) would be necessary to continue improving things in this direction.