Review and update readme

[eitan101]

Shalom Miki,

I merged my changing, please review them and update the docs.

I tried to commit every change separately so the commit log can give you quite good view of the changes.

• add v3 transformers
• remove agentId
• add ExConvNotification....getMyRole() function
• add ms.MessagingEvent...isMe() function
• change the env vars name in the example.

[miki2826]

done