Changing the way we mattermost handles URLs. team.domain.com becomes domain.com/team.

Renaming team.Name to team.DisplayName and team.Domain to team.Name.
So: team.Name -> url safe name. team.DisplayName -> nice name for users

api/templates/invite_subject.html

@@ -1 +1 @@
-{{define "invite_subject"}}{{ .Props.SenderName }} invited you to join {{ .Props.TeamName }} Team on {{.SiteName}}{{end}}
+{{define "invite_subject"}}{{ .Props.SenderName }} invited you to join {{ .Props.TeamDisplayName }} Team on {{.SiteName}}{{end}}