closes#3309, refs #3229
- adds different message depending on status
- doesn't delete the new user if the problem was an email error
- filters the 2 lists based on all statuses
Closes#3246
- Add a UserValidator to the validation engine that runs a set
of validations based on the user status.
- Added validations for invited users and active users.
Closes#3079
- new controller and template for invite-new-user-modal
- actually triggers email invite via POST /ghost/api/v0.1/users/
- setting default language value (on the client) when creating a user
- only available role is "Author" - pending 3196
- updates to UsersIndexController to allow dynamic property calculation and template rending
