JSON outputs are added to all commands, use `--json` to
get JSON output.

Following error codes are added to differenciate between errors.
Any other Unknown errors will have return code 1

ERROR_SAME_CONFIG             = 2
ERROR_ALL_NODES_STATUS_NOT_OK = 3
ERROR_PARTIAL_SUCCESS         = 4
ERROR_WEBHOOK_ALREADY_EXISTS  = 5
ERROR_WEBHOOK_NOT_EXISTS      = 6
ERROR_INVALID_CONFIG          = 7
ERROR_WEBHOOK_SYNC_FAILED     = 8
ERROR_CONFIG_SYNC_FAILED      = 9

Also hidden `node-` commands in the help message.

BUG: 1357753
Change-Id: I962b5435c8a448b4573059da0eae42f3f93cc97e
Signed-off-by: Aravinda VK <avishwan@redhat.com>
Reviewed-on: http://review.gluster.org/15867
Smoke: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Prashanth Pai <ppai@redhat.com>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>

Refer README.md for documentation.

BUG: 1342356
Change-Id: Ic88504177137136bbb4b8b2c304ecc4af9bcfe30
Signed-off-by: Aravinda VK <avishwan@redhat.com>
Reviewed-on: http://review.gluster.org/14627
Reviewed-by: Prashanth Pai <ppai@redhat.com>
Reviewed-by: Niels de Vos <ndevos@redhat.com>
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>