[Therion] plan cross-section

[marco corvi]

On Mon, 2010-07-19 at 23:40 +0200, Stacho Mudrak wrote:
> I am not sure, I understand your problem correctly, but would it help
> you, if cross section scraps could be also from other, than "none"
> projection?
> 
that's fine for vertical caves, where cross-sections 
are horizontal and have projection plan. 

infact i changed the test in thdb2d to allow
scraps with projections "plan" as well as "none".
then i had to add the north symbol as image.

there might be similar problems for vertical
cross-sections ... 
(not sure how to go about that).

marco