"Members" team

[jace]

Like "Owners", organizations should have a "Members" team that is the default team for anyone who is a member of the organization. All owners should be members by default.

The members team does not provide administrative access. It's instead the default team for anywhere that access has to be restricted in any way (filing expense reports in Kharcha or posting to a discussion group). The Members team is used in situations where managing teams is too much detail.

An app that does not have access to an organization's teams can still be aware of the existence of Owners and Members (and a user's membership in these) and can therefore be reasonably functional until team access is granted.

[jace]

Superceeded by #33. A generic "members" team isn't very useful. Apps should instead be able to make private teams for their specific need.

For instance, "members" means one thing on the job board (deciding who can post on behalf of the company), and another on a discussion board (deciding who can post to the group).

[jace]

Re-opening this as the use case described in #108 is a problem. Parking #33 for now.

[jace]

As brought up in #151, the notion of "member" of an organization has changed from "member of any team in the organization" to just "member of the Members team". This change needs to reflect in four places:

1. In Lastuser's User model, which has a helper method to return the organizations a user is a member of.
2. In Lastuser's API, which returns org memberships in the user info.
3. In Flask-Lastuser, which provides a UserBase that has identical methods to Lastuser's User model.
4. In the userinfo JSON dictionary persisted to database in all apps, if that app had organizations in the scope requested.

We need to confirm all cases are (a) correctly updated or (b) in the case of (4) confirmed irrelevant.

[jace]

With #118, members will switch to a role rather than a team. The other semantics described in the previous comment remain valid.

[jace]

As per #232, teams are going away entirely with only organizations and roles remaining, until those are removed as well. This ticket is no longer relevant.