Use bucket name in SASL if username omitted

Change-Id: Idd4837b33dfb63b7834436e6a9d6f5302ce3d31c
Reviewed-on: http://review.couchbase.org/28532
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Display effective IO backend in 'cbc-version'

Change-Id: Id3ba6ad2a529eedac89b8c2330e63a0a1a04149f
Reviewed-on: http://review.couchbase.org/28488
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>