0.15.6

As with all 0.15.x releases, the old API is effectively frozen. Changes listed are for the beta API unless explicitly labelled

Changes to old and new API

• the default Web Transport can now catch and handle errors appropriately

New API changes

• ES 7+ features were removed and replaced with ES6 features. For more information please see the docs README: https://github.com/onsip/SIP.js/tree/master/docs#compatibility
• Registerer: fully flesh out delegate
• fixed race between reinvite and BYE that could typically occur in transfer scenarios with Music on Hold
• Session: tie close to state machine
• Session: fix ACK error handling
• Session Description Handler: make error handling more robust