1. Add new-style python wrapper to most classes that were previously wrapped in yadeWrapper.cpp. Let me know if this breaks something for you.

NOTE: it is possible that compilation will be slower since YADE_CLASS_BASE_ATTRS expands to lot of template code. Our choice could be to move thie YADE_CLASS_BASE_ATTRS to implementation files and provide declaration-only macro in the header, but it would mean massive refactoring.