Multi-line:
  phone registers as individual hgs+audio@
    and via AOR


Capabilities:

- throw away all conflicts
- don't merge services when there are capability conflicts
  expose the individual services with their unique addresses
- don't merge services when there are capability conflicts
  expose the individual services each with a common address
  that forks.


Maximum capability that can be selected via caller preferences.

Minimum capability that will always be available.