[ANSI-Smalltalk] Wiki setup

[Paolo Bonzini]

I placed some links at http://smalltalk.gnu.org/wiki/main-page, and 
dumping some thoughts at http://smalltalk.gnu.org/wiki/ansi-smalltalk 
--- feel free to edit both of course.

For the proposed extension modules, maintainers for dialects that 
already implement those "topics" should set up if possible a link to 
relevant on-line documentation.

Paolo