InstanceInteropHelper improvements
InstanceInteropHelper improvements

* Added multiple file transfering in a single ssh session
* Leveled up ssh.open() and close() invocations in class methods

Improves blueprint instance-interop-helper

Change-Id: Ia57c60bcdc3f1bafd33ca58ea98d0f56e895192e

tellesnobrega/sahara,egafford/sahara,ekasitk/sahara,zhangjunli177/sahara,egafford/sahara,esikachev/scenario,esikachev/scenario,keedio/sahara,matips/iosr-2015,esikachev/sahara-backup,tellesnobrega/storm_plugin,keedio/sahara,xme1226/sahara,crobby/sahara,openstack/sahara,mapr/sahara,rnirmal/savanna,mapr/sahara,mapr/sahara,xme1226/sahara,esikachev/scenario,citrix-openstack-build/sahara,crobby/sahara,ekasitk/sahara,keedio/sahara,matips/iosr-2015,zhujzhuo/Sahara,ekasitk/sahara,redhat-openstack/sahara,bigfootproject/sahara,rnirmal/savanna,citrix-openstack-build/sahara,esikachev/sahara-backup,esikachev/sahara-backup,henaras/sahara,redhat-openstack/sahara,redhat-openstack/sahara,tellesnobrega/storm_plugin,bigfootproject/sahara,zhujzhuo/Sahara,henaras/sahara,zhangjunli177/sahara,tellesnobrega/sahara,matips/iosr-2015,bigfootproject/sahara,openstack/sahara,zhujzhuo/Sahara,crobby/sahara,henaras/sahara,xme1226/sahara,zhangjunli177/sahara,citrix-openstack-build/sahara,tellesnobrega/storm_plugin