i18n logistration

This is i18n of all things logistration. I've included translator's comments where possible to make the usage of strings clear. As far as myself, Sarina, Andy, and DB know, there's no good way to include translator's comments in our Underscore templates; I'm open to suggestions on this.

@AlasdairSwan and @dianakhuang, could one of you take a look at this when you have a moment?
This and the above are changes Sylvia has suggested in the past, but I haven't spoken with her about all the strings yet. Would you rather I leave these copy changes out until I speak with her?