Support for passing the path&filename of the settings.ces file as an argument of the conveyor.exe file, by command line execution.
By default, the path is always the same  "../CAD_conveyor/settings.ces"
Small changes and fixes
Large number of changes.
- old variables, unused, have been removed;
- all the old part of code for generating particles has been removed, because now the creation is delegated to the ChEmitter emitter object;
- code updated to support the new Chrono::Engine method for casting shared pointers, with the DynamicCastTo<>(). Read the new demo_sharedpointers.cpp for info on this.
- other small changes here and there.