Better handling / support for root site

[cameronterry]

Dark Matter currently does not fully support a scenario where some one has configured WordPress to use a different root, but defining a different value for BLOG_ID_CURRENT_SITE.

define( 'BLOG_ID_CURRENT_SITE', 1 );

If this is done, then Dark Matter may present options to map domain for the Site ID 1 (the most common "root" site) and then no longer offer options for new "root" site in WordPress. The fix is likely to change the principle of the plugin's architecture to no longer treat the "root" site as a special case and to provide full domain mapping options across all site's regardless.

This would directly impact the resolution for the enhancement requested here, #45. As the all individual sites could have mapped domains, to view all domains would require a flag on the CLI to distinguish between controlling mapped domains for a site versus mapped domains across a WordPress network.