Fix bug with fin marking guide.  If a rocket has some split fins
asymetrically placed around the rocket, the fin marking lines might not
be drawn in the wrap.  I simplified the algorithm used so first we
determine what angle the split in the wrap is, then we position each
line relative to it.
Merge pull request #38 from kruland2607/bug-print-fin-template

Fix bug with fin marking guide.  If a rocket has some split fins