Release-0.4.0

This release has some pretty big changes.

The first is due to #298, which adds the ability to use Autowiring in a forward-only context. Specifically, it is now possible to construct Autowired<X> where X is declared but not defined. It's also possible to now to autowire members while in teardown by specifying a lambda that takes a CoreContext as an argument, as so:

CoreContext::NotifyWhenAutowired([] (CoreContext* ctxt) { AutowiredFast<X> x(ctxt); });

Note that AutowiredFast must be used in this case, because you won't have a shared pointer to the context during teardown.

The biggest breaking change, however, is due to #292, that AutoPacketFactory will no longer issue packets which recursively descend into subcontexts. If this behavior is still desired, it will need to be explicitly emulated with a packet relay.

In order to prevent mismatches, #311 has been merged in order to ensure that requests for 0.3.x are not incorrectly satisfied by version 0.4.0.