Team Creation Enhancements

[michaelpelletier]

Follow up from some of the feature created in #49

• When creating a team you should be able to specify what roles are available for that team. Eg: Germany doesn't have Aliens.
• When creating a team you should be able to specify what income levels mean to them. Eg: Income Level 5 for the US is 9 Credits but for Brazil it's 8, and for Russia it's 7.
• Flags don't currently support team names with multiple words because of the flag image naming convention. Along those same lines, we probably want to have some names "Standard"? Eg: Is it USA or United States? or United States of America? We could always treat it as an "Internal name" and a "display name" but I don't super love that idea for this. It would make things easier though for different time eras or options. Eg: Russia always has the short name of "russia" for internal code use, but with the display it could be "Russia", or "The Russian Federation", or "The USSR" or whatever.
• We also want to handle the Seed data in a better way.
• Aliens need a flag, or a few different options for flags.
• Media may also need one, or some kind of icon. (Tracked in Allow news to be a team #62)

[FifthSurprise]

Leaving a note here: I'm coming around to your way of thinking for the teams/ team_roles if only because I don't want to go too crazy and support wild weird ideas.