[Therion] infer plumbs

[Vasily Vl. Suhachev]

Hello

"infer plumbs on" not affected to vertical shot correction with loop closure

Example:
====
source
   survey test
     centerline
       infer plumbs on

       1 2 10 0 0
       2 3 10 - down
       3 4 10 0 0
       4 5 20 150 0
       5 6 10 - up

       equate 1 6

     endcenterline
   endsurvey
endsource

export model
====

-- 
  WBR, Vasily