RAA - pubsub

This code is based on something Matz described in a comment to RCR #187, which was proposing an Eiffel-inspired approach to method visibility. Matz in particular was opposed to the way in which Eiffel did selective exporting of methods, and introduced a concept he used in his graduation thesis: a publish/subscribe-based approach to method visibility.

The idea is that a class declares a profile that includes an arbitrary number of that class's methods, all of which become private. When a client object wants access to those methods, it subscribes to the corresponding profile and thus gains access to them.

See the comments at the top of the file for instructions on how to use this code.

Version 0.3 implements a few internal enhancements to improve the performance of the module.