Add a raw output option to a property queried with "wsk property get"

[l2fprod]

When called with no arguments, wsk property get shows a table like output:

whisk auth		BLAH
whisk API host		openwhisk.ng.bluemix.net
whisk API version	v1
whisk namespace		[email protected]_openwhisk-vision
whisk CLI version	2016-10-24T11:55:02+00:00
whisk API build		2016-11-08T13:28:31Z
whisk API build number	whisk-build-1683

Let's say I want to retrieve the namespace, I can use wsk property get --namespace. This output:

whisk namespace		[email protected]_openwhisk-vision

Now I have to parse this output to isolate the namespace. This leads to extra awk calls like we can see in several advanced OpenWhisk tutorials https://github.com/IBM-Bluemix/openwhisk-darkvisionapp/blob/master/processing/deploy-darkvision.sh, https://github.com/skaegi/openwhisk-package-pipeline/blob/master/deploy.sh

This would go away if the output of the get command was exactly the value of the property with no extra formatting sugar. So instead of

CURRENT_NAMESPACE=`wsk property get --namespace | awk '{print $3}'`

I would just do

CURRENT_NAMESPACE=`wsk property get --namespace`

More readable and less error prone - what if OpenWhisk decides to change the formatting of the output adding more words or spaces, my $3 would no longer match the namespace.

[rabbah]

Issue moved to apache/incubator-openwhisk-cli #407 via ZenHub