[stack] Cat Version 0.15 Release

A major new release of Cat, version 0.15.0, is now finally available
for download at http://code.google.com/p/cat-language/downloads/list

= Major New Features =

- Self types : equirecursive function types. This allows Cat to
properly infer the type of recursive programs like: "dup apply" which
has type ('A ('A self -> 'B) -> 'B)

- Type declaration verification : functions with type declarations are
compared against the type inferred by the type inference engine.

- Lambda expressions : quotations with named parameters such as \x.\y.[x y +]

- .NET interface: there are now two functions for interfacing with the
.NET framework. The "new" function constructs .NET objects has
signature "(list string -> any)". The "invoke" function calls methods
on .NET objects and has the signature "(any list string -> any any)".

= Major Upgrades =

- Full type inference, all valid programs can be inferred.

- Functions with named parameters no longer use variant lists, but
instead use a lambda elimination algorithm based on Brent Kerby's
paper at http://tunes.org/~iepos/joy.html

- The graphics library has been updated and rewritten to use the new
.NET interface.

= Remarks =

- Unfortunately the documentation is now somewhat out of sync with the
implementation, but hopefully I can fix that up over the next while.

Cheers,
Christopher