Voicemail detection; call lifecycle

Calls: Voicemail detection on outbound calls — recognise an answering machine and leave a message (fixed or composed) or hang up, with its own cost line. See Transfer and end calls.
Calls: Single call state machine with an automatic reconciler — a call can no longer get stuck in an in-progress state; stuck calls are ended with reason reconciled.
Calls: Admission is region-aware, so a call is only accepted where an agent can actually serve it.
Calls: Lower browser-call connection latency.
Developer: Account ID and Organization ID shown on the Developer page; link to API documentation.