Portability fixes * do not use Object>>asString. Not all Smalltalks implement it. * do not use Object>>name. Not all Smalltalks implement it. * do not use Dictionary keysAndValuesRemove:. Not all Smalltalks implement it. * do not use Class>>methods The semantics is different among Smalltalks. Use `Class methodDictionary values` instead. * do not modify dictionary in #at:ifAbsentPut: block!