ALLJOYN-2400 Remove duplicate call to Authenticate().
ALLJOYN-2394 bbjoin should echo command line to stdout, distinguishing itself within multipoint session
Updated release notes for 3.4.0

Change-Id: I3165304fcd9c3d0b76e7b03197e6fd279e3ffda5
Format
Update README.txt for SDKs
Correct README.txt for SDKs