Enable new users to login/signup AFTER submiting an event

[Igor Santos]

This is something important to show users the platform power and push them to include new events without placing roadblocks in the way.

1. the user is asked some basic questions about the new event;
2. after filling up we save the event with a flag saying it was from a non-registered user;
3. then, we ask if the person already has an username. If yes, we ask him to login. If not, we ask him to sign up;
4. After having the user logged in, we mark that event as from a non-verified user, if it's from a new user. If the user was already verified, we mark as a generally available user;
5. After logged in, we send the user directly to the event edit form.