Add organization and location to foreman.

This feature allows foreman to provide multi location, multi tenant and
multi organizations capablities.

the idea is that resources within foreman (e.g. hosts, subnets, users,
environments etc) can belong to one or more locations and organization,
effectivily hidding resources from users.

Organization may contain multiple locations, and Locations can belong
to multiple Organization, this is an extermily flexiable design,
however, it is up to the user to allocate the resources across the
organizations and locations.

When creating new hosts, the resources that can be consumed are only
resources in which exists in both the currently used organization and location.

fixes #1578
fixes #1593