Added a baseline test for WebGUI::International which also tests the new methods.
Fixed codespace caching in WebGUI::Operation::Help. Codespace caching is
done via symbol table lookups, and it saves doing an eval.
Implemented the same type of caching in WebGUI::International. This replaced
the in-memory cache which would slowly accumulate a complete copy of the
i18n entries as they were fetched.
