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,...

minor cleanups for cache invalidations

make sure usernames are not in the logs

[SQL optimizations] - many small optimizations

• Bookmarks have only users, not usergroups
• added caching to the settings table
• removed notice message lookups (we are not really using those)...