Minor update for cross-service URL maintenance

This release addresses a design oversight in which a child service had no means of knowing if a parent's change was related to the parent's URI changing which would thereby invalidate the child's URI even if the child service's unique ID technically could exist at the new REST endpoint. An example of this is the PortService, which may have the same name (e.g., dataFloat_out) on multiple instances of the same waveform and each waveform of course has its own unique ID.

The design change should be transparent to end users unless you used the configured$ observable to follow if a service's previous attempt was successful or not. In that case, use the success member on the returned interface to the same effect.