form: rework email confirmation

realized half the info from the signup form wasnt being stored in the JWT
used to create the account after email confirmation, and instead of
adding them, the -whole request- from the browser is stored temporarily
by the server, indexed by a smaller JWT that only includes the invite
code. Someone complained on reddit about me storing the password in the
JWT a while back, and although security-wise that isn't an issue (only
the server can decrypt the token), it doesn't happen anymore. Happy?

storage.go

@@ -274,12 +274,11 @@ type Invite struct {
 	UserMinutes   int       `json:"user-minutes,omitempty"`
 	SendTo        string    `json:"email"`
 	// Used to be stored as formatted time, now as Unix.
-	UsedBy           [][]string                 `json:"used-by"`
-	Notify           map[string]map[string]bool `json:"notify"`
-	Profile          string                     `json:"profile"`
-	Label            string                     `json:"label,omitempty"`
-	ConfirmationKeys map[string]newUserDTO      `json:"-"` // map of JWT confirmation keys to their original requests
-	Captchas         map[string]*captcha.Data   // Map of Captcha IDs to answers
+	UsedBy   [][]string                 `json:"used-by"`
+	Notify   map[string]map[string]bool `json:"notify"`
+	Profile  string                     `json:"profile"`
+	Label    string                     `json:"label,omitempty"`
+	Captchas map[string]*captcha.Data   // Map of Captcha IDs to answers
 }
 
 type Lang struct {