Next step in refactoring JSGlobalObject: Added JSVariableObject class,
and factored symbol-table-related code into it. (JSGlobalObject doesn't
use the symbol table code yet, though.)
Layout and JS tests, and testapi, pass. SunSpider reports no regression.
WebCore:
Reviewed by Sam Weinig.
Added some namespace qualifications and a forwarding header, now that
KJS::Node is sometimes #included in WebCore by JavaScriptCore headers.