User preferences and meta data

Some user data is store on the user meta and some in the user options.
On a single site this does not make a difference, but on a multisite this could be improved. Settings store in the user meta are available across all subsites of a multisite. Settings in user options only apply to one subsite.

Current state.

User Meta:
- Display Name
- Locale
- Phone (personal, work), email (personal, work), address (personal, work) etc
- Biography (description)
- Notifications

User Options:
- User Status
- Workload Status
- Availability
- Roles
- Allowed Sources
- Languages
- People Groups
- Gender
- Location

Todo:
Migrate gender to user meta
Migrate Notifications to user options

Questions:
Have a display name per site?