Invite internationalization broken

Hello,

I try to translate the invite plugin and i discover some problems.

Not translated e-mail message, rextdomain problem (wpmudev), some not translatable ui message.

I make patch for this. Please pay attention if apply gettext handle well strings contains n and may not handle strings rn I remove r-s from e-mail message.

Please apply my patch if possible. Thanks

patch: http://www.dds.hu/patches/wpmu/invite.patch