[Therion] Atlas origin positioning in elevation to match plan view

[Bruce Mutton]

>In fact therion support for elevation atlas is not finished yet (we
>did not need to use it for our caves). In the case of elevation just
>the x-part and z-part of the origin are used regardless of projection
>angle.


Thanks Martin
I suspected as much, and now that I know I can stop spending time on it!  :)
Bruce