* New API: Screen::Coord1dSet & Coord2dSet
* Change Scenery::rayTrace() API tu use a Coord2dSet instead of i/jmin/max
* Make Astrobj::Properties::alloc a simple bool
* Fix PATH in yorick/yorick1.in
* Got rid of yorick-specific multi-thread code.
* Support ray-tracing of a bunch of angle-specified directions, including in wYorick, and in parallel