MB-9773: Make help text more ready to use

Most of cli commands need -u and -p options

Change-Id: I7e4e374b38845c4e640270681488450ef1c62082
Reviewed-on: http://review.couchbase.org/31638
Reviewed-by: Steve Yen <steve.yen@gmail.com>
Tested-by: Bin Cui <bin.cui@gmail.com>