Editorial changes to index2.html.
Substantial changes in index3.html, new conference handling (fixing CDMA issues), using Promises, reworked examples, added use cases, addressing permissions, using constructor for TelephonyCall, push telephony service handling as appendix, reworked steps in many algorithms, etc.
As this is independent from the main spec (index.html), and serves informative purposes, I am going to merge. Later on both index2.html and index3.html can be archived.
Editorial changes to index2.html. Substantial changes in index3.html, new conference handling (fixing CDMA issues), using Promises, reworked examples, added use cases, addressing permissions, using constructor for TelephonyCall, push telephony service handling as appendix, reworked steps in many algorithms, etc.