import: (1) fixing bootstrap task. (2) importing sub structure also for external corporations. (3) adding basic structure on bootstrap:all.
fixing i18n deprecation issue.

trello: https://trello.com/c/JNUL5s5l/489-i18n-deprecation-warning

stackoverflow: http://stackoverflow.com/questions/20361428/rails-i18n-validation-deprecation-warning
fixing membership association error.

The conditions on the membership association have to be repeated in the members association of the Group model.

trello: https://trello.com/c/KSxnjFEV/490-fix-garstiger-membership-dag-association-fehler
fixing membership association issue: adding the modifications for the User model as well.
user group membership associations. Adding uniq condition for User#groups and Group#members.
user import: Um die wingolfitische Vita und damit die Gruppen-Mitgliedschaften von Wingolfiten aus PhV vertagter Wingolfsverbindungen korrekt einzutragen, benötigen wir auch die Gruppen der Aktivitates der vertagten WV. -> Mit diesem Commit werden diese auch importiert.