copied ray_tracing.{c,h}
removed modu, dot and norm_cross that moved to lsqadj.{c,h}
WARNING: change all the calls to ```ray_tracing_v2``` to ```ray_tracing```
removed ray_tracing function which is obsolete - instead ray_tracing_v2 is used everywhere
renamed ray_tracing_v2 into ray_tracing
changed ray_tracing to the new explicit arguments
updated ray_tracing.h
removed point_line_line function which used only in one place in pointpos.c but the calling function is not used anymore
added test_ray_tracing.c
added math.h and parameters.h to ray_tracing.h
fixed CMakeLists.txt
removed commented out code
added spaces around +/*
fixed some space issues and converted all to 4-space indentation
removed spaces in the arguments
changed the arguments of ray_tracing, learned the wrapping trick from Alessandro trafo.{c,h} in py_ray_tracing:
- created a new function that takes Calibration *cal and returns two vectors X,a instead of Xb,Yb,Zb and a,b,c
WARNING - this means quite a lot of changes upstream to all the calls of ray_tracing, but it makes life easier on Python binding side.
fixed #include <optv/tracking_frame_buf.h>
Merge pull request #33 from alexlib/ray_tracing_different_arguments

Ray tracing different arguments: Agreement on this has been reached ages ago. I'm merging this and closing PR #31. Still need to test #32.