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!