Ray tracing

ray_tracing.{c,h} for liboptv includes only ray_tracing.{c,h} with a single test. note that it uses the modified call to matmul function (with 2 extra arguments of n_large and m_large). 

note that point_line_line is removed as it's not used in our software anymore. there is a call from pointpos.c function which is not used elsewhere.