Only transitive dependency remains now.

Previously, would show inappropriate precision, like "0.0598134 hours ago"
or "1490532.4129 hours from now" depending on the expiration date.

This includes the generation of metadata for all hosted entities, even if there's more than one entity defined for a certain type (e.g. multiple SPs or multiple IdPs).

Still missing:

* Metadata converter moved to the admin module.
* Metadata lookup.
* Showing metadata for trusted entities.
* Downloading certificates.
* Move the "clear my discovery choices" link to the new user interface.