Proposal: Add the support of SDK command line

To add more flexibility, openwhisk deploy can add a plug-in extension framework, so other modules are able to install in terms of plugins.

A good reference is the Bluemix CLI SDK: https://github.com/IBM-Bluemix/bluemix-cli-sdk, https://clis.ng.bluemix.net/ui/home.html.

After wskdeploy is installed, deploying entities of openwhisk becomes more like deploying plugins, which can be located locally or remotely online.