t.w.distrib : module documentation

Distributed web servers.

This is going to have to be refactored so that argument parsing is done by each subprocess and not by the main web server (i.e. GET, POST etc.).

Class	Request	A request which was received by a ResourceSubscription and sent via PB to a distributed node.
Class	Issue	Undocumented
Class	ResourceSubscription	No class docstring; 4/6 methods documented
Class	ResourcePublisher	ResourcePublisher exposes a remote API which can be used to respond to request.
Class	UserDirectory	A resource which lists available user resources and serves them as children.
Class	_ReferenceableProducerWrapper	Undocumented