Fix disk space and error handling in dockerctl restore
Fix disk space and error handling in dockerctl restore

Reduced free disk space for stateful restore to 2gb
(still 11gb for full restore). Nonzero command exit
codes only apply to the beginning of restore, but
container startup now is handled without "set -e".

Change-Id: Ifc0109e55adc7fbf30b51f5cfb259ea2ae5bf585
Partial-Bug: #1448211
Closes-Bug: #1455488

eayunstack/fuel-library,xarses/fuel-library,huntxu/fuel-library,huntxu/fuel-library,ddepaoli3/fuel-library-dev,huntxu/fuel-library,xarses/fuel-library,eayunstack/fuel-library,ddepaoli3/fuel-library-dev,stackforge/fuel-library,eayunstack/fuel-library,huntxu/fuel-library,ddepaoli3/fuel-library-dev,xarses/fuel-library,eayunstack/fuel-library,ddepaoli3/fuel-library-dev,stackforge/fuel-library,xarses/fuel-library,ddepaoli3/fuel-library-dev,stackforge/fuel-library,huntxu/fuel-library,stackforge/fuel-library,eayunstack/fuel-library