Add support for exporting Domain Access block settings.

Hello! I'm a big fan of this module, but I recently started using Domain Access module. That comes with settings so certain blocks can only appear on specific domains, and we make heavy use of this.

Unfortunately, that setting is not exported with fe_block_settings; it always comes in blank. I'm wondering if there's a more-comprehensive way to record all the settings appearing on the block form, as I suspect the module currently comes with a few hard-coded ones and [hopefully?] a hook allowing other modules to add some?

I ALSO saw some discussion about people building a new version of that module. Are any of these near completion, and do they do this? If not, I would try my handed at, at least integrating Domain Access, which is a somewhat popular module. (...And if anyone has advice on where to start with doing that, I'd be grateful.)

Thanks!