SupSuper/OpenXcom — pull request #804 by Yankes (2014-04-04 21:16:59+00:00)
Title: Fix filght path bug

Path dont get lost near pole.
Line isnt draw anymore outside globe.

To determine path I used line in 3d between two points on globe sphere. Next I split it to smaller part depending on its length (longer path have more parts). Every part is then projected back to sphere surface and draw on globe (some time line could cross centre of sphere, `a == -b` prevent that).