Added cylinder rendering
Added cone definition
Added cone properties reading
Fixed cone rendering bug
Added triangle rendering
Divided different lightsource types into separete classes
Added light source properties reading
Implemented illumination for directed on point lights
Modified sample scene
Implemented spot light illumintion; fixed bugs; finished light enhancement
Merge with light-enhancement branch
Removed unused code
Merge branch 'master' of github.com:AlexanderTolmachev/ray-tracer