remaining effect type, it didn't make much sense to leave things implemented in two separate files. Changes include: * two bug fixes (the getChild() and getMat() methods were using floats instead of shorts) * performing clamping on input values * implementing attributes using tp_getset * merging Effect and Particle functions: the Particle module exists in name only, with the Particle.New() and Particle.Get() functions remaining for backward compatibility (they are in fact identical to Effect.New() and Effect.Get() functions) * update of doc/Effect.py (including remove all old references to wave and build effects)